No trusted friend would do what you claim this person has done. I'd drop her like a bad habbit. It's hard because I know you'd have to put a few of your other friends in an ackward situation...but if you really dislike or even disapprove, you need to disassociate yourself from someone like her... especially if she's a backstabbing witch.
I just think, plain and simply, you should try to associate yourself with people that are like you...and she isn't.
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