ok my friend is around your daughters age, she said that she used to do the same thing, she suggested taking your daughter out shopping, she said to set a certain amount of money aside for her and tell her she can pick out whatever she likes, and no matter what tell her she looks good, take an interest in her music and her styles etc.. build up her confidence and make her feel good, my friend said that was you build up her confidance and make her feel good about herself, if she asks a question dont lie be as open as possable, she said that when your daughters conifidence in you is built up and she has a really good relationship with you she will open up to you sooner or later, the key is to make her feel wanted, and dont be pushy, let her come to you, dont push her or she will clam up. my friend said that when her dad started taking a close interest in her life and made her confortable around him, she opened up to him and she no longer cuts herself.