Did you and the rest of the cast get the books before everyone else?
Bonnie: Unfortunately not! Actually, the most grating thing I've ever seen in a movie is in The Devil Wears Prada, when those two little kids get the Harry Potter books ahead of time. I was like, "Are you kidding? That would never, ever, ever happen!" [JK Rowling] is so guarded, and she always wants everything to be released at the exact same time. Even the international translators would only get the books when they were already on sale, so nothing leaked out. Everybody - I mean everybody, Dan, Emma, everyone - had to wait just like you.

When you got the books, would you skip ahead to try and find the Ginny Weasley scenes?
Bonnie: I remember doing that sometimes, but then it would kind of ruin the story, so I ended up just reading as I'd read any book normally. But I remember, you know, so many people would call me or text me the day the books came out. They'd go, "Oh my god, Bonnie, have you read page two-hundred-and-whatever?" And I'm like, "No! Stop! Don't tell me anything!" That was torture!

I can't wait for the part in the last film where your mother yells at Bellatrix, "Get away from my daughter, you *****!"
Bonnie: Oh that whole scene is going to be so good. In fact, what's so great about the last film is that all the good guys bring up their game. They're like, "Actually, we'll really fight now; we're not afraid to cause damage." It's so much fun, and the best part is, we get to destroy Hogwarts!

I guess people could think that's sad, but for a lot of us, it was strangely cathartic. Like, "This has been amazing, now let's blow it up." It's kind of like when you build a sand castle and you break it down.

Do you also have a Ginny Weasley action figure?
Bonnie: [Laughing] No! Bloody hell! But I think my grandmother does. She showed it to me, and I was like, "Oh, uh, that's cool, Grandma." But I've got nothing from the actual set. They kept everything under lock and key. At the end of the day, everyone's wands were literally checked in.

Everyone kept asking if I have my Quidditch shirt, or if I have my wand, and I don't! I have a wand, but it's not the real thing - it's a merchandised one.

Are you seeing any films while you visit New York?
Bonnie: I'm actually seeing Dan [Radcliffe] in How to Succeed tonight! I'm quite excited because he has to sing and dance, and people don't realize he's been practicing for like two years. Anytime he had free time on the Harry Potter set, he'd be singing and dancing. People don't realize when Dan wants to do something, he tries to do it two hundred percent. I'm dying to see the show.

Your parents are jewelry designers, so was it always assumed you'd go into the arts?
Bonnie: Yeah. When I was younger, my brother went to art school, just as my parents went to art school. I was brought up in such a crazy environment. We wouldn't ever go on holiday and go to the beach. It would be like, "Okay, now we're going to every museum and every gallery we can find." So I did want to study fashion design, or maybe product design. But then I saw that breaking into fashion is really hard - not like breaking into film isn't, but I had an advantage there.

Are you still drawn to fashion design?
Bonnie: The idea that I love is how it connects to so many other things. Like when you're an actress stepping into a character, clothes can help you do that - they can help you create a character even for your everyday life. So I try to pick things that aren't following trends, but that lend themselves a bit more to performance.

This season in London, you were in Katie Eary's fashion show. How'd it go?
Bonnie: It was so weird! First of all, she's a menswear designer, and a good friend of the family, so she asked if I'd just come - not be in it, just attend! But when I got there, they were like, "Oh, well Bonnie's already here, let's strap her into this outfit! Very involved hair, makeup, these shoes that were like sneakers but with heels, and giant straps so every time I walked they would rub together. I can't believe I didn't fall. It was actually a lot of fun because it was so weird, until I realized my dad and other family friends were there. When they saw me walk by them on the catwalk, they started cheering! I was like "No! Stop! Please!"

Can we expect you to walk again next season?
Bonnie: This was a total exception. Now that I know how scary it is, I really don't think so.

Do you have a stylist for events?
Bonnie: No, I always pick my own clothes. I get it from my Mom; we know what we like and what we don't like!