I'm going through a similar problem with a "friend" whose just gone through a divorce. She complained for years about her bad marriage, and I would give her suggestions... finally I was just suggesting she find someone who can make her happy. Then she got the divorce, and just continued on and on, won't date anyone new, won't take any measures I think clearly would make her life more comfortable right now.

One day I was having a crisis and went to her to talk and could see she was totally disinterested and instead wanted to go over the same issues she has with the divorce... I'm taking a break from her right now. I've been trying to kindly just change the topic and or avoid her all together until things blow over. Not sure this is a good thing or not, she actually seems quite mad at me now.