“She's done it for a role, and I think it was a very brave decision and I think it really paid off,” Poppy told ET. “I think she looks absolutely beautiful with it, and I think it will just, you know, she will be so much happier in the movie getting into that role and becoming that character and that's what it's all about being an actress. So I'm just really proud of her to have taken that leap.”
While she wasn’t there for the actual buzz cut, Poppy did say she was only a phone call away.
“On FaceTime, and I was like but she looks... beyond, like, beyond,” the actress recalled.
As for whether or not she’d rock the look herself, Poppy admitted that a shaved head isn’t for everyone.
“I would say in hindsight I would [shave my head], but I don't think it would come out as well. It would be, it would probably be a disaster,” she noted.
The famous sisters offer each other advice for rocking the red carpet, and Poppy said the Suicide Squad star, 24, had some helpful suggestions for her.
“I've seen her now do a few incredible movies,” Poppy said, “and she was like, 'Just make sure you wear something that makes you comfortable, be happy, enjoy every minute of it.' I feel very blessed and very lucky to be here. I've been trying to be an actress for a long time, so now that it’s... feels like it's finally happening I'm like... it's like a real 'pinch me' moment.”
For more from the King Arthur premiere, watch the clip below!
King Arthur: Legend of the Sword premieres May 12.