Get together with her and have HER write down 5 positive things about her and then have her say them OUTLOUD every morning when she gets up and every evening when she goes to bed.
That's a hard one. I have issues myself but I have been told that changing the inner voice helps. She has been programed to do bad "self talk" because that's all she's ever heard. I'd be willing to talk her too if she wants. :) sometimes knowing that there's someone out there going through the same thing....it helps to have that support :)
can kinda just cure itself overtime really. My sis has picked on her own looks all her life. (while she is good looking). But it makes no diffrence that it comes from me really. Have to be validated by everyone els, like the world, (sadly). Even if it seems futile to say anything really, I still do. When she meets a guy (or girl if that is her thing) that treats her like a princess basicly im sure most if not all would vanish really.