If the house is in joint names and held in such a way that it will pass to her automatically, or if it was left to her in the Will, AND he had no sole name savings where the bank will ask for a Grant of Probate, then she probably doesn't need it. Whoever she contacts to do anything will tell her if she needs a Grant - e.g. the Solicitors in her sale, the bank when she goes to change his accounts, or any share registrars, etc.....