Friends trouble its Crazyyyyyyyyyyyyy?

I'd say go with your gut on this. It sounds like you don't trust her, and feeling used is a lousy feeling. If you tell her something and she blabs to the mean people, they can use that against you. Only you can determine this for yourself, but I think the best thing is to cut her out of your life. The guy she likes, likes you...sticky situation. It's probably best not to get involved with him, or the girl you're talking about could cause some problems for you. What do YOU think is the best thing for you to do?