Interview: Chronicles of Georgie's life as she grows up in public

Yorkshire actress Georgie Henley is 15, but has already starred in two films which took a total of 700m at box offices worldwide. She has spent much of her childhood on set, and is known to millions as cherub-faced Lucy Pevensie in the Narnia films.

Today however, she might be best described as unrecognisable. We meet in a suite at the Dorchester in London, where she is promoting the third instalment in the series – The Chronicles of Narnia: The Voyage of the Dawn Treader.

Gone are the chubby cheeks and schoolgirl bob, but she seems also to have bypassed any teen awkwardness and proceeded straight to Confident Young Woman. Her long brown hair is teased into glamorous waves. She wears a floaty blouse, a leather mini and flats. Her fair skin is refreshingly free of fake tan, and minimal make-up allows the scattered freckles on her nose to show through.

She looks stylish beyond her years, and perfectly strikes the balance between glamour and age-appropriate dressing. Of course, just as Georgie has grown up, so has Lucy, who takes centre stage in The Voyage of the Dawn Treader. Whereas the actors who play Lucy's siblings have always been a little older than their characters, Georgie and Lucy are the same age, and have, in a sense, grown up together.

"Lucy goes through a lot in this film," she says. "I think people will be really surprised because she is quite different. She's less sweet and I think that's just due to adolescence. It happens to every teenage girl. And I was really aware of trying to make her relateable for every teenage girl.

"I've always been the same age as Lucy while I've been playing her and I think that makes a difference, especially being a girl, because your mindset changes quite a bit as you grow."

Not only did Georgie get to grow up with Lucy, but she got to discover Narnia with her for the first time, a moment many children have surely fantasised about.

"The director of the first film, Andrew Adamson, was very focused on preserving real emotion, on seeing things for the first time, and having, like, a real sense of wonder," she says. "So he didn't actually show me the set of Narnia where the lamppost is until we shot it. I was blindfolded and guided into my place, and he told me to just walk around, that the camera would follow me. And so I turned around and I saw it for the first time." Her eyes widen in wonder, just as they do in the scene she's describing. "It was in a studio but it was ridiculously real. And so what you see is my real reaction to everything. It was incredible."

As a young child, Georgie didn't harbour any particularly strong ambitions to act, and her parents certainly didn't choose that particular path for her. Growing up in Ilkley, she had a normal, quiet upbringing, and her only forays into acting were local plays and school productions. She was seven when she first auditioned for the role of Lucy. Unlike many other child stars, she has the air of a fairly normal schoolgirl. After our interview, she tells me, she's got her French homework to tackle.

She talks fondly of her school chums and a little less fondly of double maths. She is embarrassed at how easily she gets starstruck. She speaks with an eloquence beyond her years, but peppers her sentences with teenage words, from "humongous" to the ubiquitous "like". Still, Georgie is undoubtedly more adult than the average 15-year-old. Does she feel more mature than her friends? "I feel like I have a certain level of maturity in different areas to my friends.I've spent a lot of time with adults around me. I was the youngest person in the vicinity for six months at a time. You don't realise it until you look back on it, but it was weird.

"And then you go back home and you're surrounded by a primary school of children. When you're the youngest on a film set you do get babied a little bit."

She went to secondary school for just one term before leaving to film the second Narnia film over a period of six months. "That was difficult for me," she says. "I had to make as many friends as possible and I only had about 12 weeks with them. It took me a while to fit in but I'm fine and I have a great set of friends."

There's something of the young Emma Watson about her, in her natural beauty, intelligence and determination not to get sucked into the fame vortex. Another child star who has cleaned up at the box office, Watson appears on the cover of this month's Vogue looking very grown-up indeed, and, as the last instalment of Harry Potter nears, looks to be making the transition from child to adult star fairly smoothly. Like Emma, Georgie has been kept on a short leash by her parents.Throughout filming, she gets three hours of tutoring each day.

Her mother chaperones her, and is with her today, but sits outside the room while we talk. Since promoting the second film in 2008, Henley has been given the freedom to talk to journalists unsupervised. However, she's noticed that the questions these days often take a much more personal line.

"I've noticed that three years on from being 12, people want to know more about your personal life, especially as a girl.

"People want to know about your faith, they want to know about boys. It's fine to an extent, as long as they're not probing."

Although she definitely wants to pursue a career in acting, Georgie is level-headed about the fickle nature of the profession.

"It's one thing saying you want to act, but you've got to think of back-up options. I'd love to teach. I'm also creative so anything musical would be great as well, and I'd love to experiment with writing. But acting is definitely the thing. I'd love to do something that's the polar opposite of Narnia for my next project. So maybe something really modern, smaller."

Where other child stars might have the future all mapped out, this one is, for now, enjoying not knowing what's coming next.

The Chronicles of Narnia: The Voyage of the Dawn Treader is released on Thursday December 9.

Children's classics on the screen

The Chronicles of Narnia is a series of seven fantasy novels for children writtn by CS Lewis in the late 1940s and early 1950s. They have sold more than 100 million copies worldwide and been translated into 47 different languages. The books follow the four Pevensie children as they discover the secret kingdom of Narnia.

Although CS Lewis did not want his books filmed, it has been done four times, three of them for television. Most recently Disney produced The Lion, the Witch and the Wardrobe and Prince Caspian.

The first is one of the top 25 grossing films ever. Disney pulled out of the third chapter for budget reasons and 20th Century Fox took over.