Ladies she may be unaware she is talking too much. I was a member of a small quilt group we were all new. Some days after a welcome cup of coffee I would talk non stop. They all started joking with me. Problem was I drank decaf at home and my first drink at group was full strength. It was a caffeine boost. Also I live alone only talk to my dogs after a life time of teaching and talking non stop all day. The group just laugh now and the friend I sit next to would switch off until I asked her a question. Now adays I have a full coffee drink before I leave home or get to group.
The chatterer I get annoyed with is the one who plays different people in the group up against each other. We had one who would go around the group in a loud voice ask each the same question and then compare our replies and discuss them. We ended up with her sitting near to a lady who should have worn a hearing aid and never did. Periodically the deaf lady would 'grunt' and it satisfied the chatterbox.
Good luck in your problem solving . Why not suggest she reads this thread.