A friend of mine has a daughter who is a qualified nurse and a qualified teacher. Many years ago she had a romance with a man who led her up the garden path, and turned out to be married. Since then she has lived with her parents, claiming to have mental health problems. She apparently made a couple of half-hearted 'suicide attempts' years ago. They provide her with a car, and pay for her holidays and living costs.. She does little in the house, and spends her time taking courses, mainly online. She has gained numerous computer qualifications, and a degree in Egyptology (which involved many holidays to Egypt) She occasionally takes a part-time job, but runs for the hills if they offer full time, claiming that the stress is too much for her. Personally, I think she is a leech!
Both her parents are in their 80s. They seem to be reasonably happy with the situation, and have never tried to resolve it, as far as I know.
I often wonder if, when the gravy train stops and her parents die, she will make a miraculous recovery from her problems and get a job.