Joan Jett (the real one) is such a bad ass. Apparently, she’s been active in seeing that her biopic would be a blast and Joan is concerned that Kristen Stewart (who portrays her in the film) might not be up to the challenge of playing her.

Before the production of “The Runaways,” Joan’s camp made a statement on her website saying, “While Joan is not involved with the casting decisions, she is eager to see Kristen’s work and meet with her about the upcoming role.” And wadjaknow…Jett did made several trips to the set to check out Kristen’s acting chops and if she could pull of being Joan Jett. She also gave first-hand lessons and actually made Kristen Stewart cry on set.

An insider said, “Joan just wants Kristen to play an authentic version of herself, so she needled her a little bit too much. But she apologized when she realized how upset Kristen got. They’re like mother and daughter now.”