Father's not-legal-wife took over and shut the eldest child out. She would not allow the nursing staff to tell eldest child the status of Father's condition. I got a text that Father's fake wife and Father's brother made the decision to pull the plug and his time was short. No notification. No consultation.
Whomever is the medical Power of Attorney, be it your Dad's partner or his brother, they can make the medical decision to stop any more medical care.
There must be a back story here especially when you wrote "Dad's Fake Wife". I have a feeling there's been an icy situation for some time. Lack of communications for years?
Would you sue Dad's brother if you found it he made the final call???
b) How would it help?
You are clearly very angry with your father's female partner. Would you like to say more about why? Meanwhile, I'm very sorry for your loss.