No offense... but, if I were in your position, I'd ignore your mom and
I'd tell the kids to pay no attention to "the crazy old lady." ... I really would!
She's not going to change her thinking. So, maybe, by acknowledging that it is she;
and not them who has the problem... they may not feel so rejected and dejected.
That's just my take on this.
What your mother is doing is favoratizm and it's not only wrong, but abusive behavior, because a child will remember and grow-up remembering being rejected and cause all types of problems when they are adult.
It breaks my heart to say this, but, to protect them from this type of abusive behavior, because it is abusive (rejection), I would keep the kid's away from grandma's house, until she realizes that her behavior towards the kids is unexceptable.
She will take notice and if she approaches you, tell her that due to her showing favoritizm among the grandchildren, it's necessary to protect the kids from realizing that their grandma is rejecting them. Best wishes!
It is sad for the children, but there are many mothers and even dads that do this, i know that the know what they are doing ,and it is wrong, but i hate to tell you she will not change, it is just best to visit less than have the children hurt, the more you talk about it, she will just get worse, also some parents also have favorite children and show it which is sad, but that is life for some people, and they just cant or wont change i am so sorry for you and your family luck jo
I have 19 grandchildren, and this is the perfect example as to why I moved to florida and allow my children to run their own lives. This is the nightmare I was trying to avoid and am so so sooo glad I did! There is only one of me and not nearly enough to go around without one of my kids feeling slighted or like one of the others are favored over the rest of em. I just avoided the whole darn mess!