Kristen Stewart Talks ‘Runaways’ On ‘Tonight Show’

'We're both, like, riddled with tics,' 'The Runaways' star said of the rocker she plays in the biopic.

Kristen Stewart got her girl power on while filming her new flick “The Runaways,” which opens on March 19. While shooting the film about the groundbreaking 1970s group , she got to hang with “Twilight” co-star Dakota Fanning and ex-Runaway Joan Jett. When Stewart stopped by “The Tonight Show with Jay Leno” on Wednesday night, she admitted that Jett — who Stewart portrays in the film — taught her a lot about being an uber-cool rock chick.

“I was really lucky to have her be into the project and be open to it,” she said of Jett’s involvement.

When Stewart first arrived on set, she was worried that Jett would be skeptical of her casting. “I was so intimidated. I was about to do ‘New Moon.’ I sort of thought she was going to look at me and [want to replace me because I had long hair]. We spent three weeks together, [and] every day she told me things I could never say.”

Eventually the pair bonded, but Stewart remained determined to nail her portrayal of Jett (which Jett has said she did ). “Playing a real person, you always feel the pressure,” she explained. “It’s, like, if I don’t get every little thing right I’m going to kill myself. And we have very different tics. We’re both, like, ridden with tics, but they’re a completely different set of them.

“She stretches all the time,” Stewart continued. “She’s got a hunch, but a cool one. She was on set everyday. I would have felt like such a fraud. There’s only so much a script and footage and photos can show you.”

Later in the interview Stewart mentioned Fanning, who plays Cherie Currie in the biopic. She said the two are now as thick as thieves, even if they are very different people. “Dakota is one of my best friends and she’s a great girl,” Stewart said. “She speaks very well and she presents herself in a certain way, and I have an incapability of acting if I’m not acting. I wear my heart on my sleeve.”