When family member has completely distorted view of how others think about her: time for reality check?

My mother has a completely twisted view of how others view her. Time for a reality check? If so, how to give it to her?

1. My sister in law loathes my mother (and me). My mother is sad that my brother and SIL never invite her to visit, and when she visits anyway, the visits are required to be only very short. They ignore her requests to go on vacation together (and vacation with their friends). SIL also ignores my mother's phone calls and emails.

My mother says, "I haven't done anything wrong and I'm a perfect mother in law."

That doesn't matter, SIL loathes her (and me).

My mother also blames me for not visiting my brother and SIL more. (I'm not invited because SIL hates me.)

What to do?

2. My mother is a horrible cook. Her mother (my grandmother) tells people that she is, and word got back to my mother. When I visit my mother, she serves food that is inedible, and I almost never eat it.

My mother says, "I'm a great cook and when people say that I'm a bad cook, it's false."

Time for another reality check?

Not trying to be hurtful, but if my mother's view of herself matched others' views of her, then maybe she could address the causes of issues with people and have better relationships going forward. She's completely delusional, and that only results in continued bad relationships with people.