Good luck, cat. I remember the shellshocked feeling I had when I realized that my home state, for all intents and purposes, was more than willing to help my Nmother rob me blind. It was terrifying.
There are things you can do, but unfortunately they all take some effort.
There've also been cases where adult children whose parents abused them during childhood successfully petitioned the court, or whatever it was called, to be 'excused' [that's not the word either] from the obligation to support their former abuser in old age merely because of a blood relationship. That's tricky, though, and depends so much on the people involved. Courts are a travesty.
Good luck. And thanks, I did feel as though I was just totally inept at the explanation for some reason.