I could see here being an ISFP, definitely has the whole ISFP performer thing going, along with the Emo Pop/Rock/Metal / Lady Gaga thing. That she was comfortable on TV as a child would make me think she's probably more of an Extrovert. The comfort to perform on stage comes with maturity for most Introverts I know.
I would actually go more ESFP. I think she puts on this image of introversion. She gets stuck in Se-Te loops and tends to open her mouth before thinking about the future consequence (inferior Ni). Talking about masturbation in interviews and magazines, posing in lingerie on magazine covers, flashing her breasts with 'x' tape on her nipples in public, trash talking people like Miley Cyrus, claiming she's better than Miley Cyrus etcetera... There is a lot of Fi there "I do what I want" but I definitely think she's an Se-dom.
I think she is introverted. She is very reserved in interviews. She also seems very private. She is probably more comfortable on stage. I mean, Marilyn Manson does all those things on stage and he is introverted. She doesn't seem to be feeding off the energy of her surroundings and she seems not to enjoy being in the public eye which probably explains some of her offensive behavior while she is so. I would classify her as an ISFP.
Then again.....she seems to the signature INFP expression on her face. Only part of the face shows emotion and is otherwise expressionless.
She seems like a Fi dom. I've seen a few of her interviews and she's always talking about being true to herself and how she hated how they wouldn't let her be herself when she was younger blahblah. Type 4 Fi dom, most probably an ISFP.