The main reason why I think she may be a manipulator, is because I ever befriended one too. Through the situation is different, I do feel the same thing like what are you feeling right now: guilty, but despise her; you don't even trust her. And based on your short description about her, she sound like one.

Of course I don't know if I right or not since I never meet her at all. I only want to warn you. If she is indeed a manipulator, better not deal with her or try to minimize all your interaction with her. For your own mental health sake.