how about

start with a doctor's appt? For you at least, if not her.

That "protective custody" might have been your best option.

A set of rules, with the "PC" as a last backup option, might be a good try.

If nothing else, YOU get family counselling for yourself. You'll at least get info on all kinds of help. She could benefit from a life skills course.

Some things here you CAN do, and others need a professional edge.

A word on disabilities: My sister had ms for about 20 years, and died of it in April. One of the best things I learned was this:

"Having a disability doesn't make someone a saint."

If you are walking on eggshells, you don't have to do that any more.

I liked Catnapper's suggestion - actions (like the laundry dumping) show her what she CAN'T do.

Just make sure that whatever consequences you say- that you carry through with it, so she learns to respect what you say - that you'll do what you say you will.

I'll shut up now - good luck!