And don't forget your son. Do whatever you can to help mitigate the damage she has done. As to your son's "gender relevance" question... Now you have the answer. She doesn't give a d@mn about him.
What probably happened is your DIL went to your demon for some advice. With a small scratch opened the demon injected her with poison -- and continues to do so. Perhaps you could see a lawyer about gettind a restraining order placed on your STBXW to not contact DIL. She is not family anymore. Your son could file regarding her mental stability and in fear of his child's life. I know this is a dirty thing to do and it will anger DIL but your grandchild and son deserve any chance they can get to reconcile the marriage in that case.
M:11 | T:12 | Status: Married 4C's of WAS communication: Cool, Calm, Collected and CONFIDENT