Coping with friend's betrayal?

Perhaps she feels as though she did nothing wrong. Or perhaps she feels that if she pretends she did nothing wrong, you'll go along with it and she can feel better about whatever awful thing she did. Regardless, you should tell her how you feel. If this doesn't solve anything, ignore her and move on. Unfortunately, some people are just jerks. Even people we wholeheartedly trust. I just hope it doesn't break your faith in humanity.