She has health as well as mental problems and she keeps saying no one cares, will discuss any of her conditions or what physicians have found and has called all family, started confrontations and told us to all stay away from her. She lives alone and is very depressed so I am afraid for her. No POA designated and she refuses but is very clear she is going to have things her way and we should all go away. Her behavior is scary and not sure if she would hurt herself however she has expressed her disinterest in life....
Family can show they care by sending cards, those nice old fashioned printed messages which are still used despite electronic communication domination now.
They're something she can read and reread, if she remembers that she has them, and perhaps be convinced her family does care, although it does sound as if she's pretty entrenched in her perception that she's alone in life.
You could call Adult Protective Services and report her as a vulnerable adult. You could call her doctor, if you know who s/he is and express your concern about her mental state (they can't GIVE you information, but you can give them information ).