@Dacquoise
Excellent post.
Wise words.
She is not a good woman or mother rhat is how she treats you as she does.
She's not a good grandmother because she excludes your children too.
She drops in at HER convience.
It is all about her.
I simply wouldn't allow her in my home and she will have to entertain at hers or out at lunch.
HER choice.
Whatever you do find the strength to protect yourself from being used as skivvy carer in the future.
I have told this story before of a family I know that had a large valuable house on a large site.
4 children, with one golden son.
He had ALWAYS been given everything and the girls always had to work very hard at multiple jobs through university.
They were a comfortably off family.
On the grounds of the house in a corner far from the house a little bungalow was built for the parents and without a conversation, the house was signed over to the son.
A very valuable house on a very large urban site. Gorgeous gardens.
He and his young family moved in.
The three daughters were furious and there was a huge falling out.
The parents were there for the son and helped out with childcare during those tough early years and then out of the blue they decided to take a job in another city and SOLD the home.
So this couple are now elderly living in an area nearby 3 daughters, that 10 years on have absolutely nothing to do with them.
They were a very respected family and everyone knowing their business and their humiliation...has been a shocking grief for them.
Privately there has been very little sympathy due to the way they thought they could treat their daughters.
You owe your mother absolutely nothing.
As @daq has wisely written, put clear distance between you and your mother so there isn't any confusion as to what your relationship is.
Keep posting.