77 years old....
Enjoy her crabby self while she is still with us.
My MIL was a royal pain in the butt.
After a car accident that had her in a coma for about a week...even my youngest son said.... I will take her pinching my friends butts any time she wants over her not being here at all.
Now as for dealing with her... I would go for a walk, to another room, anyplace that she wasn't...and vent alot. When I would lay down at night I could sleep well because I knew that I was doing right..even though she would say...so in so does this and that.
Being an easy, safe target... we get the frustration they have inside. They vent at us...we can vent to each other. I heard every word you typed *LOL*