((((OE))))

So sorry to read that you're in a triggered state. I read through the thread before posting. Your OP started with wondering how to tell your parents about not visiting more. And you did it! You told your dad that it's because you aren't welcome there.

It's a weight off, though this distraught after effect. Your sister doesn't sound like a very nice person. Your brother seems tuned in where he told her there was no way she was taking control legally speaking of their finances when she asked him about declaring your dad incompetent.
At least you have your brother for some understanding especially in a more historical context.