Yuck! I know what it's like to have a "friend" try to get approval for their bad behaviour. Using you to make her self feel better about what she's doing is low. She's taking advantage of your kindness, overstaying her welcome and drinking with you when she knows that makes things hard for you. You don't need people like that in your life - nobody does. But especially right now when you've got your own stuff to deal with, don't feel guilty for stepping away from this woman. She's not your problem. I'm sorry that she didn't grow, as you had hoped for her. You were let down when you saw that she hadn't changed a bit, and that hurts. You gave her the benefit of the doubt, you don't owe her more.