Ah Joelle, I see what you mean. She must be related...the best thing to do is just act as if she is not in the room. Seriously. That is how I treat my SIL...I do not acknowledge her presence. After a while she just goes away...not quietly, but she goes away.
I do not talk to her, I talk around her. I have no time for this woman. She is nuts. Literally. She's manipulative to the point of distraction for everyone in the family. That's why I blew my stack yesterday at my brother. This visit here is to set up hospice for my mom, not to garner sympathy for some disease that his wife does not have.
If she had what she says she has, she could not be doing the job she supposedly does. I know that. And if the subject comes up today at lunch, I am going to bring that up to my brother.
So Joelle..good luck to you. Take care of yourself.