I have my narcissist mother living in my home and would gladly give up my inheritance for someone to take her off my hands. If anyone has the chance to have someone else take care of them, I think you should let them, and run as fast as you can because it is hell. If it depends on the nursing home getting your inheritance, then let them have it. There are some ways around that tho. But I had to feel guilty and take this mean woman that is my mom out of the nursing home and she is in her mind, bearly, but enought to say "I am not going back" and that is all it takes and you are stuck.
Get her a nice little apartment somewhere if she is so sane, and move all her nice possessions back in with her, and inform some adult protective services agency to keep an eye on her. Oh, really, what do I know. How do you divorce your parents?
So was money (inheritance) a consideration in bringing her home? It certainly would be mine. If your mother is still with it enough, how about having her see a psychiatrist and counselor? My mom is good natured, but when she is having a delusional confrontational episode, I say things calmly like "that is not acceptable, Mom, open your eyes, come back to the room, and get in the real world. The world with your squirrels, kitties, Andre Rieu..." It seems to have an effect. How far does someone have to be "gone" for you to call them on their maddening and cruel behavior.
Anyway, you being a nursing home RN, you must have a few answers up your sleeve, and perhaps this has happened at your facility before with other families. The "home didn't work out, we're back" situation.