It all makes sense. The enabler (or one of them) is her new girlfriend from college , who also is a big drinker (don't know more other than she also gets drunk frequently). She's got a "drinking buddy" and she's her great friend now and that basically replaced our relationship (she gets a lot of her needs fulfilled by her - friendship, drinking buddy, conversation, hanging out time, etc). So even that is enough to help her move on.
It's funny, it's not like I want her to leave and be miserable. I want her to be healthy. I want her to be happy. I worry that her path may lead her to despair. She is special to me and I know that we can't work in this situation, but I hope she one day will "come to" and be at peace with herself.
During her 5 month break from drinking, I remember how clear, lively, and different she was. She has such potential inside. It would be wonderful to see that girl get a chance again, instead of the girl that exists when she's in this horrible loop.