He is active and thinks he is fine mentally, but he has become very forgetful and increasingly aggressive and cruel towards her. She is and has been the only care giver for him since his wife died. Other siblings refuse to take him because of his behavior. What can i do for her? She is at wits end and making her miserable.
If it is dementia, your dad won't be able to live alone for long. Convincing someone of that can be difficult. There is persuasion with the help of the doctor and there are ways to petition the court once you think you can prove his is incompetent. I would consult with an attorney about that.
It's not your sister's fault. I would discuss this with other family members and agree on a plan to find the cause and help your dad, even when they don't realize they need it.
Becoming guardian/conservator for someone will run you at least $4,000 in attorney fees, bonding, and court fees. (ask me how I know.....)
Parents will refuse our help when they need it most, so make a plan to get around it that isn't as obvious as a nuclear bomb.
It doesn't help to make them feel ambushed by a group, insulted by uppity children (who are usually over 40!), and told what to do.
For my mom, it was better to work with solving some of her immediate problems. She had a nice long list of things that bothered her, and all the changes were about taking care of those problems.
==Being afraid in her home alone. This happened a lot.
==Worrying about burglars and being attacked
==Don't you want to stop buying groceries?
==I know you are afraid of getting lost in the house. Let's fix that.
==Would you like somebody else to do your laundry?
==How great is it there's a security guard here! Wow!
==I just noticed there are no stairs here, and there's two elevators!
Mom also lived in this fantasy world where she was the Grande Dame of Society with a constant stream of cocktail parties and game nights, suppers, and shows every night of the week. And making her sisters jealous. The truth was she was a recluse in a hoarder house with zero visitors.
The other card I played was about that.
==Imagine all the fun you'll have here.
==Look at how beautiful it is. So clean!
==I bet you'll have Gentlemen Callers in a week.
==You can go to the beauty shop as often as you want
==Every night has a club meeting, movie, game night, entertainers. How fun! When was the last time you had any of that?
==I bet you can't wait to send pictures of this place back to your sisters. They'll be pea green jealous. It's definitely nicer than their homes.
==That lady is petting a therapy dog. You've always loved dogs haven't you? You haven't had a dog in how long?
Honey catches more flies than vinegar.....