I'm not sure how much you can help her, that's a pretty tall order. But it would be good just to be a friend and try to understand. The issue here is self-esteem: when someone doesn't have a strong sense of their own value, the tendency is to look outside of themselves -- to get feedback from others -- in order to sort of "see themselves" reflected in others' responses. This is why people seek the approval of others, and it's also why some people (especially girls) go to extreme lengths to make themselves beautiful by the standards they think that guys hold. So it's compensation: compensating for a kind of inner void by trying to grasp on to positive feedback from the outside. The trouble is, that kind of grasping is never satisfying: you can never get enough of the right kind of feedback from others to make you feel OK inside, it's like trying to fill a bottomless well with a small pitcher. Ultimately, she needs to see that this is futile and start working on developing a clearer internal self-concept, so she doesn't have to rely on such extremes to compensate. That can take years. At best, you can be an informed and supportive friend -- you aren't really going to be able to instantly "rewire" her self-esteem.