Aging Parents Trying To Get Out Of Being Caregivers For Intellectually Disabled Aunt

Location: Florida.

Hello, I'm not living at home anymore as I am living in another state, but as the title states, my parents are suffering currently due to caring for my dad's sister. He is the 2nd oldest sibling of 4 (the sister in question is the oldest). My parents are in their 70s and are at the point of being unable to care for her, she is around 78~ or so. Currently my younger brother lives with them and supports them, but also wants her out.

She has been... destructive to say the least. She has "episodes" of anger for little reason, she lies a lot, breaks things, yells/screams at parents, forgets things, etc. You name it. They never wanted to take her in in the first place, but they're too nice and kept her for over 15 years, my dad's other siblings want absolutely 0 to do with her, even going so far as to say they're willing to let her be in the streets as bad as that sounds. Recently, they have had enough due to an issue that occurred, it was bad, but not necessary to add here I think. They were even thinking of just taking her to a hospital after another massive outburst and just leaving her there when the discharge papers come. It's that bad.

Things they have tried:

• Made calls to the APD (Florida Agency for Persons with Disabilities), they just give my parents the runaround, literally they were in a call a few days ago where they looped a few numbers, e.g., (they call and speak to someone who says it's the wrong department, then directs them to call person #2 --> now they're told to call person #3 --> now they say call person #1 again --> repeat)
• Tried/trying to find a home for her (but they can't afford it)

To add, they are experiencing financial hardship due to her, and are at risk of losing their house.

Key things:

• My dad is NOT her legal guardian, only the payee for social security. But it isn't enough because they have had to dip into their own savings just to provide adequate care for her.
• They do NOT have training to be caregivers.
• She cannot care for herself generally-speaking. She does have the capability to do things such as make coffee, use the bathroom, shower, turn on her TV (but doesn't know how to navigate apps/channels on newer TVs), etc. Things like that, but nothing else. One example, we live around the corner from a family friend's house, literally a 2 minute walk, once a few years ago, she wanted to leave their house and come back home after a party (she left without saying anything and no one paid much attention when it happened), and she ended up getting lost.
  

Other than research, I can't do much myself unless it's sending them some money when I can or whatever which I'm happy to do. To them, it feels unbearable and they are at a loss of what to do, the gov is tying their hands behind their backs while also telling them they can't just abandon her while providing 0 support. The thing is, they DON'T want to support her anymore, they are done, they just want to live the rest of their lives in peace.

Any advice or experience is welcome.