boy,,,, a really tough spot you are in..
Since I am pretty blunt, I would probably just ask...
With my Mom, she had althiemers, so my father pretty much decided things... but with my Dad, he choose not to have a will - though he did choose everything for his funeral prior to passing... they were both in their 80's..it was surreal to go thru the process of choosing prior, it was very difficult but his request had to be honored.

I wish you the best..