If you'd met me before, I was unbelievably shy at school," she says. "You always get that one person who can go through a whole week without talking to anyone and that was me, sitting in the corner all by myself. It's pretty sad really. It got to the extent where I would be too scared to ask for help if I was stuck in class. I was that kind of girl. But doing this film has definitely brought out my confidence."

"My favourite thing about playing Cho was being able to be popular. She's popular among the boys and the girls and, um, that's not something that happens in real life."

"What's beautiful about today is that you have a room full of, in my opinion, some of the finest actors in the world, in one scene," explains director David Yates, who is on his first Potter tour of duty. And as David Thewlis and Gary Oldman pass me by, deep in conversation, while Brendan Gleeson, in full costume as the visually challenged 'Mad Eye' Moody, and Julie Walters loiter in the background, it's hard to disagree.

It will be very strange, but it will be quite liberating in a way. If there were going to be an infinite number of Harry Potters, I don't think I could do it. It's nice, knowing that there's seven. I've always thought that's a definite goal to try and hit.