Like Viola, her character in ''She's the Man," teen star Amanda Bynes is a young woman in flux. In the film, Viola masquerades as her twin brother to play on the boys' soccer team at his school. Much of its comedy comes from the tension between her awkward attempts to be a cool guy and the moments her girlish voice and enthusiasm show through her disguise.
Similarly, dolled up for a post-interview photo shoot, Bynes sports thick fake lashes on saucer-big green eyes that recall a young Sally Field; her legs are the lean, deeply tanned limbs of a model. But she squirms like a high school student in study hall, fidgeting with her highlighted hair and green velvet pants. She embodies both everything her teen fans dream of being and everything they know they really are, and they love her for it.
Having come of age in the spotlight, Bynes, 19, is savvy enough to appreciate the strength of her Everygirl appeal. She struggles to maintain it in an industry notoriously perilous for its child stars, while also striving to mature into roles with more substance.
''I recently wanted to get an acting coach, or whatever, just to work on my craft, quote-unquote," she says. ''My dad was like, 'Why would you want somebody to change who you are and turn you into something different?' And I think the reason kids relate to me is because I do seem like them, because I am more similar to them than some, you know, socialite or whatever."
Bynes, who grew up in California (her mother was a dental assistant and her father a dentist who moonlighted as a stand-up comedian), has spent half her life in front of the camera. After taking comedy classes, at age 10 she was given a regular role on Nickelodeon's preteen sketch comedy show, ''All That." By age 13, she had her own variety program, ''The Amanda Show." In 2002, she made the leap to the big screen, playing Frankie Muniz's best friend in ''Big Fat Liar," and from Nickelodeon's kiddie domain to the tween network WB, where she still stars with Jennie Garth in ''What I Like About You."
On the TV show, Bynes's character must adjust to living with her older sister after their father moves to Japan. Similarly, in Bynes's recent films -- 2003's ''What a Girl Wants," in which she travels to England to search for her father, and her latest movie -- she has played characters removed from their natural element and forced to get by on smarts and spunk. It's a feeling Bynes understands well.
''I've always chosen roles that I relate to at the time, because I don't know who I am yet," she says. ''I am still finding myself, and I think that's why I have fun doing these things -- because through doing them, I grow up every time a little bit."
Because she still feels she's developing her acting skills, Bynes didn't see herself as a leader on her new film's cast of young actors, many of whom were older but less experienced than she was. ''I have worked for a long time, but I feel just as clueless as anyone," she says. ''I don't know what I'm doing. I have no real technique. I'm not a method actor. I am getting better as I go, and I'm picking up things. I learn as much from everyone else around me."
Her costars would give her a bit more credit than that. For Channing Tatum, who segued from model to actor with 2005's ''Coach Carter," working with Bynes was a fantastic opportunity.
''I've learned a ridiculous amount from that little girl," says Tatum, 25. ''When you do talk to her, you'll see how smart she is and how really put-together she is for a young girl. I've never considered myself a comedic actor, and I learned so much from her."
Her latest role stretches Bynes far beyond what she's given to do on the WB. Based on William Shakespeare's ''Twelfth Night," Ewan and Jack Leslie's script is smarter than average, thanks in part to their collaboration with Karen McCullah Lutz and Kirsten Smith, who wrote ''10 Things I Hate About You" and ''Legally Blonde." Andy Fickman provides deft directing that features plenty of fast-paced soccer sequences. And indie comedian David Cross gives a sly performance as a bumbling school principal that could become a cult classic.
While the film's love triangle relies on the kind of coincidences and misunderstandings that fueled countless ''Three's Company" episodes, most were adapted from Shakespeare. In a nutshell: Viola (dressed as her twin brother Sebastian) falls for her roommate Duke, played by Tatum, while helping him woo Olivia (Laura Ramsey) in exchange for soccer lessons she hopes will help her play just as well as the guys. Olivia, of course, has a thing for Sebastian, as played by Viola, enraging the real Sebastian's girlfriend, Monique (Alex Breckenridge).
The film has an upbeat girl-power message that never feels too heavy-handed. It was an important draw for Bynes, who tries to be a role model for her young fans. ''It's about following your dream and about being yourself, and how you can try all day long to be cool and whatever," she says. ''But in the end, the people who you'll want to love you will love you anyway."
It's a complicated thing, being a role model and sex symbol for fans barely old enough to attend the PG-13 films you star in. At a Boston preview screening, the film seemed innocent compared with the questions giddy fans asked during a post-film Q&A with its stars. There were requests for Tatum to dance, do a flip, take his shirt off, and give hugs, and questions about whether Bynes has a boyfriend (no) and what their onscreen kiss felt like.
And so Bynes could be offering the best advice of all when she talks about holding on to what's left of her own childhood for as long as she can.
''I still want to be a kid," she says. ''People want to rush you so much because they want to make money off of you, but nobody really cares about you as a person. And my family was so supportive of being, like, 'Just do what makes you happy, and be yourself.' "