No, dont ask her not to, tell her you will not discuss it and you would appreciate her not to bring anything up regarding your W again.
(A) keeping family out of it is key and it will only add more bad feelings and it borders on gossip.
(B) You are not detached enough to hear these things because you have now made 2 posts about your W and HER issues/problems. So, 2 mentions of your W in one day. We are back to square one of you not mentioning your W at all.
If you were detached anything you hear about her would go in one ear and out the other and you wouldnt give it a second thought. And you wouldnt have to worry about giving it a second thought if you removed yourself from any conversation about your W from a third party source. Especially if that 3rd party source is one of HER family members.
Your W's SIL might act all friendly and conversational with you but anything that is said will go right back to your W and it might not be in the correct context. It sort of speaks volumes that your SIL would bring up what your W is saying at all, dont you think?
