I thin Oma66 has the best response, kind and considerate. You don't know what compels this woman to chat non-stop, it very well could be her way of trying to be friendly, reaching out to your group. She may be very lonely or living a troubled life and looking for some peace and solace from a group of women. I think it is hard to walk into a group that has been together for a while because there is already an air of companionship in a group that I'm not a part of. She may be simply introducing herself, letting you know what she has accomplished in case someone else finds something about her that they can connect with. I wouldn't assume she is just a know-it-all. Give her a chance, friendship is a precious commodity that a lot of people don't have.