But she admits she will ‘miss the people and the buzz of being on a massive film’, adding, ‘It was quite a bitter-sweet thing to film Susan and Peter’s departure because it was quite true to life.I think it’s sad, but it’s also realistic for Susan at that stage in her life to go back into the real world and forget about Narnia,’ she says. But, to be honest, although I’ve had a really wonderful time making the movies, I sort of feel ready to move on.
‘I was quite worried about not being able to keep up with the boys,’ she admits, ‘so, on the quiet, I had twice as many riding lessons as anyone else before we went out to film in Prague.
When the battle scene was being choreographed, we started a body count of all the people we had “slain” and I was doing very well,’ she adds with a grin.
And there’s still a tantalising C S Lewis parallel, for she happens to be studying at the same college – Magdalen – where the writer was an English tutor for 30 years.
‘It wasn’t in my consciousness when I applied, but there’s a wonderful symmetry to it – possibly I’m even being taught by people who were taught by him,’ she speculates excitedly.
Another book, The Voyage of the Dawn Treader, is currently in preproduction, but the two eldest children, Peter and Susan, won’t appear in it, for at the end of Prince Caspian they are told by the lion Aslan that they won’t be coming back to the magic because they are too old.
And although Peter makes an appearance in the final Narnia book, The Last Battle, by then Susan is no longer a friend of Narnia because ‘she’s interested in nothing except nylons and lipstick and invitations’.‘At least I didn’t have to run up and down hills wearing a suit of armour, like the boys,’ she points out.‘There were 500 people on the battlefield one day and it was so hot and crazy that there were some injuries – but nothing too bad.’ The filming proved to be a particularly poignant time for Anna, because Prince Caspian will mark her swan song as Susan; as all devotees of C S Lewis’s seven chronicles of Narnia know, Susan only appears in two of the novels.Mention of the line that left readers in no doubt what Lewis thought of frivolous girls provokes a giggle from this blue-eyed, brown-haired teenager in her hoop earrings and black, high-heeled boots.‘I’m not totally “nylons and lipstick” orientated like Susan,’ she protests playfully.As Anna puts it, ‘I was 13 when I had my first audition for Susan; 15 when I made the first movie; 16 at the end of the shoot; 17 when it was released; 18 when I filmed the sequel, Prince Caspian, and now I’m 19.’ The comparisons with 18-year-old Emma Watson, who plays Hermione in the Harry Potter films, are irresistible.