mixed-up in popularity. Options

[cori-catastrophe]

so i have this really good friend named anna. she's fourteen, but she's acts very older. lately, she's been getting into some bad things. she sells pot at school and there are numerous guys asking her if she would have sex with them. i'm pretty sure she has an eating disorder as well. she's a really good girl, but this year she's all mixed up in the "popular", shall we say, group of people. i am really worried about her. she has a very smal body and i don't think it can take very much of this all at one time. she's almost fainted numerous times. i want to tell her to chill out, but i'm afraid she'll get angry with me. plus, i don't even know if she would listen to me at all or if it would solve or change anything. there are only a few people that know, me being one of them. she told one of mine and her friends, micheal and micheal freaked out on her and told her it was unhealthy and so-on. she got mad at him and said he was acting liker her dad. she tells me everything she wont tell other people, and i don't want to loose her trust by getting her in trouble. i've already told my mom the kinds of things she's getting into, but my mom said that there was nothing that she could really do about it. help?