I am so sorry to hear this.
My dad and his second wife were consumed by the same ball of conspiracy.
A difficult pill to swallow.
In my dad's case, it was early onset dementia. My mother in law was a dumbarse and didn't know better. Between the two of them, the ingredients mixed themselves into a soup of paranoid.
If easily possible, I would help her find an out of area attorney so she could spill her beans about the case, and let that pan out however it does (which it probably wont), but you keep your distance. I.e. you find a name you don't know, have her call it, and you keep out.
My dad and his new wife knew better than any hospital in the region.
Instead of helping her, consider helping yourself delineate strong lines of engagement. They are sick. There is only so much you can do.
Talking sense into the unreasonable and expecting sense will lead down a path of pain, even if meant of good intention.
I am really really sorry.
Good luck.
Ron