Remove AA suggestions from the picture. Remove alcohol from the picture.
Now what would you do if you see the same thing happening to a friend outside of AA?
A friend that is at a stage of being vulnerable...
Peter said it best I think.
When (if) you talk with her...remember she may be at a point of "feeling" a need to be comforted and you need do what is right. Help her away from him and she could grasp on to you. Replacement of one for the other isn't good either.
Be a friend but be watchful that you don't get pulled in by her feeling of need.