If the hospital will not let him go home......is this not kidnapping? Call the FBI.
Why? Do you want this woman to have an FBI agent laugh in her face? Get serious, the FBI is not going to get involved in this.
The fault for adult children being estranged from him could be the fault on either side. Several years ago there was a case in Virginia where the father - or was it both parents? - left the home to their five children but still expected to live in it until death. No sooner had they turned it over than the children kicked them out.