. When she calls me names I tell her I am a chip off the old block. She huffs. Then I ask her if she wants more coffee or whatever she giggles and its over. My mother moved back in the area last year to help me with everything (am expecting my first grandchild in Nov). My grandmother said some nasty things one day to her (that she can't remember) now my mom won't help at all, I work 7 days a week. My grandfather died a 2 years ago and my mom was devastated. She didn't have much to do with him my whole life. My grandmother paid for his funeral and was not married to him for almost 50 years. The point is how do I deal
with someone exasperating?
I have found that reframing the issue can really help in enlisting assistance from relatives. Emphasize that that your grandmother has changed, and that you, not just your grandmother need the help.
Also, at least initially spell things out for your mom, I had my mother start doing basic house cleaning chores and shopping, that way she could take a load off me even when it was difficult for her to be around my grandmother (like your grandmother, mine can be hard on the people around her.)
Finally, the only way I have found to deal with my grandmothers negativity and criticism sounds a lot like yours, I give a noncommittal, nonjudgmental reply and change the subject. And when she is being really bitter, I make sure she is as safe and comfortable as possible and I make myself busy in another part of the house. I am having to learn that I cannot always make everything right for her.