[stomachmonkey]

Does the Uncle in law have a history of being a POS?

Has he done things that cause you to not trust him to do the right thing?

Sounds like you are judging him for things he has not and may never do.

I've been around Alzheimers patients, at some point they are no longer there. It's very sad and can be difficult on the family. They can also persist in a nearly vegetative state for years.

If it were me in that state I would want my wife to continue to enjoy life.

If he did divorce her would she not be entitled to alimony which would go to her care?

Where in Canada do they live? They could be in a community property jurisdiction which makes the whole thing mute.