How can caregivers, one being the court appointed adult son, obtain possession of an incapacitated person's home before her estate is out of money?

I'm not certain what you're asking here. Your mother in law will continue to own her home -- that should not change during her incapacity unless there's a reason to sell the home.  Medical assistance (not medicare), if she is eligible and needs it to pay for skilled nursing care in a facility, will have a claim on her estate (which may include her home) for reimbursement.  Your question sounds like one of someone wanting to shelter assets from medical assistance.  More informaiton is needed.  I would recommend that you contact an attorney who provides estate or elder law planning in your area.  if you are in Western PA, feel free to contact my office.