As for the MIL, just show her you won't discuss the divorce or relationship or anything with her. Your MIL is as big a brat as the W. In fact, I don't see much that you need to discuss with your MIL at the moment.
H 34 W 29 BD 3/12/18 Divorce Busted Spring 19
It is not things that bother us, but the stories we tell ourselves about things.