You have too many other people in there with this friendship. Talk to this woman, tell her your concerns and stay away from the third parties, they are not part of any relationship you have with this woman!

If you do not see her or do anything with her and she is just telling you stories, do you mind that? She obviously has a problem and needs to tell you stories. If you don't like that, tell her you don't believe the stories and would like to talk about something else.

I do not understand why you are talking to this woman/friends with her in the first place? What is in it for you?