Would you really want your wife to stay with you because of financial dependance?
I'd be grateful to FIL that he is making it possible for your DD's to live in a decent home instead of some run-down rental for the half of their lives that they will be with their mother.
Her friends and family are not talking her into divorce--a good number have tried to talk her out of it, and been shunned by her for their trouble. She has made that decision, and I think that enough time has passed and enough roadblocks have been put up that she is resolved to go through with it.
