I don't agree that she needs to get it all out of her system so she should be allowed to dump it all on you! You are not a therapist. You are a friend, and as such, your job is to support her. Your job is not to sit there and listen to things you do not feel comfortable hearing. I agree with the other poster who said that you should call her and tell her that she cannot say such things in front of you anymore or else you cannot speak to her. She may balk, as you'll be throwing up a boundary, so be prepared for that, and do not back down. If she still needs someone to talk to, encourage her to seek counseling.