I am watching a longtime friend of my DH have his life ruined by his DF's family. Mary is the youngest daughter of a large family; her parents divorced years ago. Her mother now has diabetes and is on dialysis 3 times a week. Although there are other siblings living in the same city, no one will do the slightest thing for their mother, so either Mary or DH's friend do everything for her: drive to doctor's appts, drive to dialysis, fill prescriptions, go to appointments with Medicare/Medicaid to work out benefits, make sure she takes her medications and eats right. And mom won't do the slightest thing to take care of herself or to relieve any of the burden on them. Have her dialysis at a center that's only a 30 minute drive away instead of 90minutes? Nope. Take the medical transport bus to a few appointments rather than have Mary drive her? No way. If Mary tries to stand up to her, mom cries and wails and calls the other siblings, who then call Mary and abuse her on the phone. The best part is that DH's friend does his best to be supportive and does some amount of driving mom himself, even though it means he misses work. And because he's a different ethnicity from Mary and her family, they treat him like dirt, insult him to his face, etc. They desperately want to move out of that city but Mary is worried that no one will do anything for her mother and she'll die, and of course it will be Mary's fault.
This is 99% Mary's issue, but she's afraid to call her family's bluff and refuse their demands because the stakes are so high, and it's ruining her life and that of her DF.