Maybe you should think of her as an assistant of sorts. She comes and takes the kids to school and just talks to you because she doesn't know what else to do. You could always tell her that when she tells you about all the going ons in her life it bothers you and would like for her to keep it to just essential info.
But let's also think of her as the assistant that just started crying, perhaps you would hand her a tissue and say I am sorry you are upset today. Maybe even rub her shoulder, if you don't want to attach tooo much. Think of her as someone you know and that you have to "work" with because circumstances call for it, but you don't need to be overly friendly with.
Just a thought.
kat
Me-53(and learning!) S24, S21, D18, D17 Just keep swimming, Just keep swimming. Dory