Having her Hermione chestnut curls lopped off in a New York salon last August hasn't cropped the career of young British actress Emma Watson one little bit. While the release next weekend of part one of the Harry Potter finale marks the end of her role as the fictional heroine, it's all elementary for Miss Watson.

She currently graces the cover of Vogue, has a contract with Storm model agency, and, at just 20 years' old, already has an estimated £20m in the bank. Several of those millions come from her two-year advertising campaign for Burberry in which (along with younger brother and fellow model Alex) she fitted perfectly creative director Christopher Bailey's re-invented image of a classic label that had previously been appropriated by the string vest and pitbull terrier set.

Despite the glamorous assignments, there is something of the bookish Her­mione Grainger in the real-life actress who is now in her second year studying English literature at Brown, in Providence, Rhode Island. A straight-A student, she turned down an offer from Cambridge as it was "too Hogwarts looking". Inevitably, she was approached on her first day at the élite Ivy League college for her autograph, but politely refused with an apologetic: "I'm here to study, and I just want to be a student... you'll be seeing me around all the time anyway."

A pragmatic streak was instilled early on from her parents Chris and Jackie (who divorced when Watson was five). Having landed the part in the first Harry Potter film when she was just 10, she recalls her mother being "fearsome" in her
insistence that it wouldn't interfere with her schooling. "I'd be filming all week and then my mum would get me out of bed on Saturday to go to school and I'd be exhausted." But neither is she the child of "pushy, pushy stage parents", she has insisted, enjoying freedoms beyond the experience of many other teenagers. She has lived in her rented flat in Islington since she was 17 and is widely travelled.

Adopting her gamine new look is seen as her most daring move to date after being contractually obliged for the past nine years of the Harry Potter series not to cut her hair. Interviewers describe her as polite, a bit posh, a bit earnest. As bluestockinged Hermione, with her prodigious intellect and cleverness, she was seen as a positive role model for schoolgirls and, so far, has studiously avoided the media attention beloved of so many vacuous celebrities. "I've had so much freedom, sometimes it was hard. My parents wanted to protect me, but they had no idea how to. I had to learn as I went and make my own mistakes." Her first non-Potter film marks her willingness to take risks. It's a small role in which she plays a young wardrobe mistress working with Marilyn Monroe and Laurence Olivier, as the king and queen of ego filmed The Prince and the Showgirl.

Watson is prepared to try new roles, but admits that her swift rise to fame has been daunting. "I went from being totally unknown and never acting professionally to being in a major movie and being very famous. It all happened so quickly, I didn't have any time to work things out. It's been pretty scary at times." But nothing a spot of wizardry and magic can't cope with.