Her head slathered with evil-looking slime, Reese Witherspoon has spent the afternoon undergoing a dramatic metamorphosis at a Los Angeles beauty salon. "How we suffer for our art," she says with a mischievous grin.

By the end of the day, Her Blondeness has been transformed into a smoldering brunette with glossy auburn highlights. She eyes herself dubiously in the mirror. "My mother's going to fre-e-eak out," says Witherspoon, whose sugarcoated drawl reverts to 100-proof syrup when she talks about her parents back home in Tennessee. "My mother is so southern. She has all these sayings—like 'Everyone's hair looks better with a few hot rollers in it!' and 'The blonder you are, the better you look!"'

But now it's past five P.M., which is Witherspoon's idea of the witching hour. "I have to go home and make dinner for my family," she says apologetically, dashing for the parking lot.

A couple of days later she e-mails me from Memphis, where she's just started rehearsals for her latest movie. She was hoping nobody would recognize her for a while, but the minute she got off the plane, strangers were calling out that they loved the hair. So much for traveling incognito.

Ever since Legally Blonde made $140 million and turned her into a household name, Witherspoon has inhabited that rarefied tier of success in which paparazzi lurk behind the bushes at your child's pre-school, tabloid reporters root through your garbage, and no disguise can prevent fans from mobbing you.

Witherspoon's admirers have certainly juiced up her career; after she struck gold with that not-so-dumb blonde Elle Woods, their loyalty catapulted the 25-year-old actress right into the $ 15million-per-picture club.

Judging by the avalanche of fan mail that ensued, Elle inspired countless girls to apply to Harvard and enter law school, and Witherspoon's burgeoning popularity even made box-office hits out of such flimsy vehicles as Legally Blonde 2 and Sweet Home Alabama—both of which earned well over $100 million worldwide. Witherspoon seemed to have perfected the art of playing lovable blondes whose true hearts triumph over whatever minor inconveniences life throws their way.

Now, however, comes the acid test. Witherspoon's latest role is among the most ambiguous and least saccharine female characters in English literature. Becky Sharp—the scheming arriviste who claws her way up the social ladder in William Makepeace Thackeray's Vanity Fair— can all too easily seem more of a villain than a heroine. Indeed, even Thackeray couldn't quite make up his mind about whether or not she killed off an unfortunate admirer.

Can the ever adorable Reese do justice to this difficult character? And even if she can, is she a sufficiently potent box-office draw to lure the masses to a period film based on a literary masterpiece set in the early 1800s? The very fact that Witherspoon is attempting such a challenge speaks volumes about her personality—and her drive.

"I think it was a really brave decision for her to do this film," says James Purefoy, an alumnus of the Royal Shakespeare Company, who joins such veteran character actors as Eileen Atkins, Jim Broadbent, Bob Hoskins, and Gabriel Byrne in the cast of Vanity Fair. "Reese could do anything she liked; why play something as unsympathetic as this? Even Reese can't get away from some of the diabolical things Becky Sharp gets up to."

This Vanity Fair was directed by Mira Nair, whose previous movies include Monsoon Wedding and Mississippi Masala. "Becky is one of the richest female characters ever written, in terms of the complexity of emotions and the journey she travels," says Nair. Born in India, the director brought an outsider's perspective to the rigid British class system that ostracizes Becky, the penniless daughter of an artist and a French chorus girl. The typical cinematic interpretation is "reeking of that English attitude," Nair says. "She got her comeuppance; they put her in her place, made her stand in the corner and face the wall. I have no time for that. Becky is very resourceful, full of beans, and very much somebody who believes in life. I've tried to make her deeply human."

"Mira said to me, 'We're going to turn this whole thing on its ear,'" Witherspoon reports. "I saw Becky as a kind of early feminist-wanting more. Attributes like ambition or desire were perceived as wicked then; now they're not. Becky is a survivor. She's definitely going to grasp every opportunity that comes her way."

And grasp she does. "If Becky were alive today, there would probably be a 12-step program for her—Ambitions Anonymous," observes Purefoy, who plays Becky's charming but feckless starter husband, Rawdon Crawley. "Nothing is ever enough for her. That's what Rawdon eventually realizes about Becky—she can never climb high enough."

The same might be said of Witherspoon, whose early success and dauntingly full life seem to epitomize the noteworthy accomplishment—more remarkable in the movie industry than elsewhere—of Having It All. Compared with most of her peers, she presents a curious anomaly in contemporary Hollywood. While other twentysomething performers generate tabloid headlines with their late-night carousing, stints in rehab, and messy love lives, Witherspoon is a decorous and resolutely private young mother who leads a home-centered life, believes in monogrammed napkins, and always sends thank-you notes. Forgoing the red carpet as well as the club scene, she is far more likely to be found taking her daughter to ballet class than making a public appearance. For a festive occasion, Witherspoon and her husband have a few friends over to their house in Los Angeles. "We like barbecues," she says brightly.

A southern debutante from an upper-middle-class family that traces its lineage to a signer of the Declaration of Independence, she figured out what she wanted very young—and made sure she got it. "I remember being such a voracious reader in kindergarten that I read all the books for the whole year in the first month," says Witherspoon, whose mama used to call her Little Miss Type A. "I am very goal-oriented."

Witherspoon met the hot young actor Ryan Phillippe at her 21st-birthday party, and by the time the evening ended she was cooing to him, "I think you're my birthday present." Unfortunately, he left at six the next morning to shoot a movie in North Carolina. "We had this very Edith Wharton courtship where we were writing letters and sending novels," Witherspoon says. "I went to visit him two months later, and I knew."

"I have cellulite. I have stretch marks. I feel intimidated by Victoria's Secret."

She was six months pregnant when they got married, and by the age of 23 she was the mother of their first child, Ava. A year ago, in between earning millions of dollars and transforming herself into an industry player, Witherspoon delivered her second child, Deacon, whom she and Phillippe refer to as Mister Dude or Baby D. She has made the family her first priority, rejecting jobs that conflict with her home life and alternating movie commitments with her husband so that one of them can always stay with the children.

Meanwhile, she has also become a producer (with Legally Blonde 2) and formed her own production company, Type A Films, to develop new material. "I like work," says Witherspoon. "If it's not hard enough, I try to make it harder. I like the process of being daunted by it, tackling it, and knowing I can do it."

And now, at the ripe old age of 28, Witherspoon is poised to tackle the next challenge. Although her box-office appeal is often compared to that of Julia Roberts, it's Meryl Streep whose crown Witherspoon covets. She has no intention of letting herself be typecast in one lightweight romantic comedy after another.

Hence the decision to play Becky Sharp, an opportunity she generated herself. A fervent admirer of Nair's work, Witherspoon called her up and said she wanted to collaborate. "I'm really in awe of her," says Witherspoon. "She had this way of interpreting sensuality in her films that is very female. It's not aggressive; it's not gratuitous. It's beautiful."

The result was Vanity Fair. "I needed an actor who could be irresistibly appealing while playing the complicated aspects of Becky," Nair explains. "That kind of appeal is an absolute must, so you don't end up making a film where everybody despises the protagonist. With Reese, it's impossible for the audience not to love her. It's the factor that makes movie stars out of actors— and Reese is a movie star."

While $ 15 million remains her fee for big studio movies, Witherspoon says, "I did Vanity Fair for practically no money. It was like an art film. I could have done romantic comedy after romantic comedy, but at what cost? You burn yourself out. You get a bunch of movies you're not proud of, and your career is over. I'm just taking my time."

Witherspoon is planning to stick around for the long haul, and she wants respect. And judging by the excited buzz that's building around Vanity Fair, it looks as if she's about to get it.

Witherspoon emerges from a fitting room at John David Ridge, a Los Angeles costume studio, with a gleeful look on her pert little face. "For June Carter Cash, I get to wear all these great clothes from the 50s and 60s, like a Western-style shirtdress and a leather coat with fur trim and a big gold buckle," she says.

After becoming a vixenish redhead for Vanity Fair, Wotherspoon is preparing to play June opposite Joaquin Phoenix as Johnny Cash in Walk the Line. But she has just discovered that her own, seriously blonde wardrobe looks all wrong with the dark tresses she acquired yesterday.

"It took me like an hour and a half to find something to wear this morning," she says. "Purple is it so far."

Wearing a purple top, a flowered white-and-purple skirt, and flat sandals, she looks very much the demure, well-dressed young mother who might be on her way to a parent-teacher conference. There is no midriff showing, and although she is surprisingly curvaceous for a five-foot-two-inch former gymnast, Witherspoon doesn't go in for visible cleavage either.

Unless she's playing Becky Sharp, that is. During the filming of Vanity Fair, a year ago, Witherspoon's body was voluptuous with pregnancy. (She was seven and a half months along when they finished shooting the film, a feat made possible by extravagant Regency gowns whose Empire waistlines helped conceal a bulging belly.) Determined to make Becky a "full-blown sensual woman," Nair was delighted her star was pregnant—but getting Witherspoon to flaunt her assets was like pulling teeth.

"When Mira starts talking about bosoms and heaving flesh, I start to sweat," Witherspoon admits sheepishly. "There's something about overt sexuality ..." She shudders. "Like it's scatological or something! I'm all about trying to make movies that have nothing to do with my body. I'm prudish and nervous. I don't have the excuse that my grandmother is watching anymore, but she's watching!" Witherspoon glances upward. "It makes me nervous when I see a woman with her midriff showing. I would never do that on purpose, and if it happened by accident I'd be mortified. I feel threatened by women who—eeewwww!"

She covers her face with her hands. "Like women on the cover of hootchy-kootchy magazines! The way I was brought up, I wasn't allowed to wear black, and I wasn't allowed to wear bikinis. And I was only allowed to wear two shades of lipstick—peach or pink. It was all about what was 'appropriate.'"

Unlike most of her peers, Witherspoon has always refused to trade on her sexuality, and she abhors revealing costumes—even on-camera. "If I ever have a bikini scene, it will become a caftan scene," she vows. "I had to do a bikini scene for Legally Blonde, and I worked out like a madwoman three hours a day. I would never do it again."

Her reasons go deeper than southern-style propriety. Witherspoon has an unusually clear grasp of the relative transience of youth and beauty—an understanding that doesn't dawn on most people until both have vanished. "I just feel that those things are evanescent," she says. "It's great that you're the sexy one today, but what are you going to do when you're not the sexy one? I study other people's careers, and I spend a lot of time thinking, What would Tom Hanks do? I'm just trying to stick around and make sure I have a career when I don't seem like the new young sexy thing."

Witherspoon has always considered herself a character actor, preferably a comedic one. "There's something timeless and important about making people laugh, about being the bright spot in their day," she says. "Funny doesn't sag."

Witherspoon also knows she is a role model to her fans. "I get a lot of response from young women who say they trust me," she reports. "I was doing some magazine thing recently where they wanted to put in all this fake hair, and I just didn't want to. I don't want to be something I'm not. I think other women really like the idea that someone's just who they are—and not trying so desperately hard to be something they're not."

Moreover, Witherspoon wants to make it very clear what she is. "I have cellulite," she says firmly. "I have stretch marks. My breasts are not what they were before I breast-fed two children. I feel intimidated by Victoria's Secret. Having all that overt sexuality thrown at me—I think a lot of women find it threatening."

"We've never been competitive with each other. Ryan is very successful."

She especially deplores the disingenuous posturing of starlets who pretend their perfection is effortless. Staying in shape is very demanding, she says: "The truth is I work dam hard at it. It's irresponsible to tell women, 'I took off the baby weight because I took some diet drink.' Then women go out and buy diet drinks! I run three miles at least four times a week. I go to the gym. I take yoga classes. I don't want to exercise four times a week, but it's my job. My worst nightmare is having to look a certain way for a movie that involves working out obsessively. I would rather drink bleach than have to have cut arms."

As she toys with an iced tea in a café near the costume studio, Witherspoon is undeniably lovely; with her wide blue eyes and her cute little nose and her flawless complexion, it's easy to see why she was cast as an irresistible love object in her only movie with Phillippe, Cruel Intentions.

But even Witherspoon was rejected at auditions: "I got 'She's too smart' a lot. I got 'She's not thin enough' a lot. I got 'She's not sexy enough' a lot."

She tries hard to be realistic about the harsh standards Hollywood imposes on women. "It's one of those endless competitions, but it's like running a race toward nothing," she says. "There's no winning. You're never going to win the thin race. You're never going to win the pretty race. You're never going to win the smart race. You're never going to win the funny race. I just want to be the best version of myself I can be."

Besides, Witherspoon has always had her brains to fall back on. Her father is a surgeon who got perfect scores on his S.A.T.'s and his MCATS, and her mother, a professor of nursing at Tennessee State University, has "like seven degrees." Witherspoon herself went to Stanford University before being lured away by the siren call of Hollywood.

"She's smart as a whip," says Alexander Payne, who directed her in Election. "There's no dumb blonde in her," adds Gary Ross, Witherspoon's director on Pleasantville. "This is a brilliant blonde who was very focused and mature at a very early age. She was always very confident and driven."

Witherspoon is exceedingly sure of herself in ways that are particularly rare among actors. "I just don't need any validation," she says calmly. "I don't need anybody telling me I'm good. I'll tell you when it's good."

She has never hesitated to assert herself, even when she was an unknown teenager and her input was greeted with a notable lack of enthusiasm by the people who employed her. "They want people they can push around," she says. "I was the girl who was always asking, 'Why?' 'Yeah, I know you want me to do that—but why?' I always thought people wanted to hear my opinions. It's only as I've become older that I've realized no one wants to hear my opinions."

She grins. "But I give them anyway. It's just blind self-confidence. I get like a little terrier about things. My mother says I should have been an attorney."

Witherspoon was only 14 when she landed her first movie role with an electrifying screen test for The Man in the Moon. "Here was this riveting, beautiful girl who just jumped off the screen," says Steve Dontanville, her longtime agent. "She was just a natural. I got on a plane and flew down to have dinner with Reese and her mother. Betty was a doll, but Reese really grilled me; she asked me all these questions. She was this very opinionated, focused person, very powerful and self-assured—a little southern spitfire."

"I have a little Napoleon complex," Witherspoon says, laughing. "Gary Ross calls me Mighty Mite. I'm a scrapper. I always come out fighting, because I always felt I had to struggle to be seen and heard. I was this little shrimp of a thing—the smallest kid in class, like a midget. I had big glasses—huge— and my vision was so bad I couldn't see the E on the eye chart. I certainly wasn't the homecoming queen or the prettiest girl in school. I was a big dork who read lots of books—but I was a popular dork because I learned how to be funny."

Witherspoon achieved success at such an early age that it's easy to forget how long it took her. "I paid my dues, I took jobs I didn't want to do—I worked very hard to get where I am," she says. "Every script since I was 18 years old had 30 pages of notes on it."

But despite all she has achieved, Witherspoon still struggles to be taken seriously in the industry. "Even now, people want to marginalize me," she says. "They want to attribute all my success to teenagers seeing my movies. I really resent it when people say, 'It's just a genre film; it's teen comedy.' It takes a lot of work to make these things have heart and resonance so they're not just empty, disposable confections. But I don't give a damn about other people's perceptions, because I'll show them. For women in this business, ascendancy is always a battle. It's scrape and claw. I just try to stick to my guns and respect myself. I want to take the ingenues aside and say, 'Value yourself! It's O.K. if you have opinions!"'

And if people don't agree with her, Witherspoon finds other ways of defying them. "I've learned the art of ignoring people," she says. "When people give you some piece of direction you don't like, you just nod and ignore it. Just don't do it! Most people just want to be heard and acknowledged, anyway."

She flashes me a dazzling smile. "Just do what you want to do," she says, her honeyed tones so silky smooth it's easy to miss the steely edge underneath. Becky Sharp would know exactly what she means.

When Reese Witherspoon and Ryan Phillippe walked up to the podium as presenters at the Academy Awards two years ago, they seemed the perfect movie-star couple-beautiful, talented, and the very personification of radiant young love. Then Phillippe handed the envelope to his petite wife to open. "You make more money than I do. Go ahead," he said.

The joke prompted much gossip in Hollywood and beyond. Witherspoon had become one of Hollywood's most bankable stars under 30—but was Phillippe envious of his wife's soaring price tag? Rumors of marital trouble intensified when he casually mentioned in an interview that he and his wife were going to therapy.

Witherspoon, who just celebrated her fifth wedding anniversary with Phillippe, is still steamed about the reaction. "I feel like that whole thing got misconstrued," she says. "People were not nice about it. They thought it connoted big dark clouds on our lives. Since when is self-improvement a negative? Why wouldn't I be interested in psychology? I like to read a lot of psychology books. I'm obsessed with child behavior; I would love to be a child psychologist."

The couple is no longer in therapy, and Witherspoon says things are going just fine. "He's literally my best friend," she says. "He makes me laugh; he makes me think about things. We're both actors, so we can commiserate about the bad things and celebrate the good aspects of it. It's a great friendship, and I feel really blessed to have a great friend as my love."

When I venture that many men get upset if their wives become more successful, Witherspoon says tartly, "Men of what generation? I think things are changing. A lot of young married people grew up in dual-income homes and had mothers who worked. The men are much more involved in child care. With my husband, it's 50-50.

"We've never been competitive with each other," she adds. "Ryan is very successful. He gets tons of offers every month, for tons of money. We're talking about enormous sums of money—and yet people think it's not important because it's not as much as me. By anyone's standards, Ryan is more than successful."

But then—because Witherspoon never forgets to charm—she gives me a conspiratorial smile and adds, "If he starts competing for female romantic-comedy roles, we're going to be in trouble."

Both Witherspoon and Phillippe, who grew up in Delaware, have parents whose enduring marriages serve as a powerful inspiration. "Marriage is hard," says Witherspoon. "I think the greatest lesson I could take from my parents' marriage or Ryan's parents' marriage is to go with the flow. You think you can't get over certain things—and you do. You only learn that through sticking with it. I had a real good idea of what a working marriage relationship is. It's not about expecting someone to make you happy every day, or to complete your life. It's a great partnership. Two individuals come together and share a life, have children, and hopefully you come out of it friends. I never thought it was easy. I still don't think it's easy."

For years, people have been asking why she settled down so early. "I met the right person for me," she says simply. "Certain things are just meant to be. We were young, but I had a lot of life experience, and so had Ryan. We both wanted to be young parents."

She turned out to be well suited for domesticity. "I'm an organization freak," says Witherspoon, a Tupperware collector whose idea of a really fun shopping destination is the Container Store. "Cleaning out a drawer ... " She sighs rapturously. "It makes me feel calm and sorted. I remember organizing my toys when I was seven years old. I remember organizing my bookshelves." Fortunately for both of them, her husband is considerably less compulsive: "He'll show me how unimportant some of the things I obsess about are. I'll get caught up in something, and he'll say, 'You can organize the refrigerator after you drop the kids off at school!'"

Witherspoon claims that parenting has helped mellow her. "It's changed me so much," she says. "I am less judgmental, more live-and-let-live, more accepting of people. You realize you're not perfect, your children are not perfect, and everyone's just struggling to get by. Motherhood is a great equalizer. It doesn't matter how cool you think you are—when you've got baby spit-up all over your back and smashed chocolate cupcake all over your jeans, you're just like every other mother."

Well, maybe not quite; unlike most women of her generation, Witherspoon is a fervent believer in the role of propriety and formality in family life. "I grew up with elegant, dignified women, and I am working every day on trying to be that for Ava," she says. "My mother was always respectable and dignified. Because my mother worked, my grandmother picked me up after school every day in her white Cadillac. She used to wear these beautiful leather driving gloves, even though she was just driving a block. She was always beautifully dressed; her bag always matched her shoes. She always had her hair done at the same beauty salon, every Tuesday for 50 years."

And Reese was always a good girl, she says. "I didn't want to rebel. My brother was very rebellious, and I promised my mother I wouldn't be a rebellious teenager."

Following in the family tradition, Witherspoon's children have been well schooled in the importance of saying "Yes, ma'am!" and "No, sir," and never sassing their elders. "People talk about what's appropriate and what's not appropriate all day long in the South," Witherspoon explains. "What is the right kind of stationery and what is the wrong kind of stationery for which occasion? Etiquette is not dead in certain places. I had to get a little bit away from it to appreciate it."

She still finds the informality of Southern California to be excruciating. "Calling teachers by their first names at school—it's just more than I can bear!" Witherspoon exclaims. "It's just so—so personal!"

"She's a lady, and it's hard because there aren't really people like that in Los Angeles, especially among actors," says Deborah Kaplan, a film writer and director whose husband, Breckin Meyer, is one of Phillippe's best friends. "People don't know what to make of it."

The southern bluebloods where Witherspoon comes from were so rigidly conventional that even her profession caused consternation. "A lot of women in town didn't like that I was an actress," she says. "It was a little—not nice."

To Witherspoon, being "not nice" is almost as bad as being "tacky" or "in poor taste," both of which approach the status of unforgivable sins. How then to understand the behavior of her older brother, John, when he broke into a neighbor's home in October 2002? John—who worked for his little sister as a chauffeur during the Filming of Sweet Home Alabama—was sentenced to two years' probation. He is now a married 32-year-old real-estate agent in Nashville.

But his arrest remains a touchy subject for Reese. "I feel like that's his business," she says. "I feel guilty that because of my success, people seem to have opinions about people in my life. I feel responsible for their lives being in a fishbowl. We're not Kennedys. We don't have a public responsibility. We're just regular folks, trying to do the best we can. People make mistakes."

When I ask about news reports that alcohol was a factor in her brother's actions on the night of the arrest, Witherspoon says carefully, "Alcoholism is a terrible disease, and it's affected my family in lots of ways, for generations."

Including her brother? "My brother is a recovering alcoholic," Witherspoon says. End of subject.

She is even more protective about the family she is building. "She really hates being a celebrity, because it invades her privacy," says Steve Dontanville.

The aggressiveness of the Los Angeles paparazzi is a particular source of concern. "I understand that public life is a choice, but hiding behind bushes at the pre-school and jumping out and frightening the children? These people are really predatory, and they have a lack of regard for children as human beings," Witherspoon says. "Every day they're at the nursery school, and they jump out and try to get a reaction on your child's face. I feel it's unfair to my kids. I'll say, 'Please don't frighten the children,' and they'll say, 'Fuck you. I don't care about you. I don't care about your children!'"

Witherspoon and Phillippe finally got so fed up with paparazzi tormenting them at home that they moved to a gated community. They may have more children, and want to provide them with a normal life. They are now thinking about leaving the Los Angeles area entirely.

"They're homebodies; you don't see them out on the circuit, in the party lane," says Marc Platt, who produced both Legally Blonde films. "They care very much about their marriage, their family life, and their professional lives. It can't be easy all the time, but whatever the strains, they wear them well. They seem very determined to have it all—and if I were a betting man, I'd bet they will."

But Witherspoon is ever mindful of the famous final lines of Vanity Fair, which Mira Nair often invoked while directing the movie. "The whole Yogic question Thackeray asks is: Which of us, having met his desire, is satisfied?" Nair says. "It's the essential question of life."

Witherspoon certainly seems to have met her heart's desire. She has her handsome husband. She has her beautiful children. She has her stellar career.

So is she satisfied? Hardly.

"I don't think this is the end of what I'm supposed to accomplish," she says, a troubled frown creasing that milky forehead. "I think it's just leading me to some path I haven't found yet. All the attention actors get—it's so unmerited. It's so insignificant, what I've done. My parents devoted their lives to taking care of people, and they couldn't enumerate all the lives they've saved. I want to carry on the legacy of compassion and caring. I feel strongly about the lack of health care in America, and I really want to help people. This is not the end of it."

"She always has a backup plan—'If I can't do this, I'm going to be a doctor,"' says Rachel Bati, a talent manager who has been a close friend since Witherspoon arrived in Hollywood. " 'Even if I do well in this business, I might still want to be a doctor; nothing lasts forever!' She wants to have the family; she wants to have the career; she could go and do the doctor thing. She's going to have it all and do it all."

Would a major movie star—even one who idolizes her parents and still talks to her mother every day—really give up the big time to work in health care? Little Miss Type A is not about to put herself on the line until she's absolutely certain.

"I'm wary of what goal I set," she says, "because then I'll have to accomplish it."