Do you have help with this from an agency? If you are in the USA, there should be a state agency to help care for people with disabilities.
I agree that you need to make sure there isn't a health condition causing this. Also, keep her from napping during the day so she is tired at night, and consider that her medications could have side effects causing this also.
If she is urinating all night she might be drinking too much water late in the day.
You can't "get" her by yourself. She has to want to fix this. When she's on board, she should first see a doc to either treat or rule out an underlying medical condition. If there are none, then look to CBT adult sleep training programs for a permanent solution. Much good info online, or ask your doc for a referral.