You all need to have an intervention. You sit them down and express remorse and sadness for their situation. Then you discuss how they have been incredibly hurtful to the family. Then you set boundaries - they will be no additional money and they need to seek counseling. If they cannot do this, they are not welcome at family events.

Op just cut the bitch off. If a family member said that about my kid they would be dead to me, and I would tell the rest of the family exactly why and that I was done, no going back. But I have a mouth on me, unlike many of these women, next time she ranted I'd tell her I hope she never has children after what she said.

How did it go today OP?