^^^ Good advice.
My thinking is: if Daughter was aware of the deal, and the amount due, and is good with all that, then subject to execution of Dad's will, you should be OK.
Additional work not approved in writing, most likely not billable.
Whether or not the daughter or other family wants to keep the car will certainly affect any further work other than agreed upon.
Example: if it was my Dad's '66 Sport Fury or Grampa's '55 Bel Air, I'd want it mint. Others may just want it done quickly and sold off.