Your mom is not in a state where she is going to even listen to anything you have to say. You could come up with the most perfect materialist understanding of what’s going on, and it’s gonna go in one ear and out the other. It’s akin to people who are sold on Young Earth Creationism or a flat earth… you can show them the science but they will simply hand wave it away as “biased scientists” or some conspiracy theory they hold on to to protect their ego. People have to be in a position where they are questioning their existing understanding or open to new ways of thinking about things.
I suggest looking into a technique called “gray rock”. Basically, it comes down to only engaging with people by giving them the most bland, uninteresting responses. Don’t give them a response good or bad, and they’ll eventually get bored of trying to engage with you. Normally I would say antisemitism, racism, etc need to be confronted; but I feel that’s more towards people with influence over others or a public setting. When it’s your mom whose gone off the deep end and you have to live with her, I think that’s a situation where you have to take care of yourself first.