We are dealing with that with my husband’s sister who is only a couple of years older than him.
Although her husband and children are present, she will not cooperate with them in her own care.
My husband (her brother) is the only one who has any influence over her.
She wants to live alone and drive her car at will even though she totaled her last one.
She claims she is perfectly healthy in spite of a long list of serious ailments and injuries.
Apparently she doesn’t have any pain from these ailments and doesn’t even remember that she has them.
It is exhausting dealing with her.