The social worker and the medical community are giving you the standard line about not wanting to get involved. But sometimes, the outside help from strangers will put a new perspective on things. In the meantime, you also do have to assure grandma that she is loved and valued too. Despite the fact that her actions are making her unlovable, she may be very scared that she can no longer really care for herself. She probably did a lot more of the caring and work around the house than most people gave her credit for- she may have even bullied her husband into doing things but without her nagging, the things might not have been done. The couple need a marriage counselor but that would be pretty hard for either of them to admit to because they are from a generation who certainly did not really in divorce. Plus, what would divorce gain anyone? You are all a family! So, start acting like family members. But that also means asking for help when help is needed and not just to air dirty laundry but to help all of you understand how hard it is to get old. I don't know how you manage to live 50% of the time- that sounds stressful itself. Figure out how everyone can work as a team on these things. Consult the medical field and the legal field. You will also need legal advice to help determine who should pay for what services. Anyway, that is what I would do to handle the situation.