The term is "quitclaim" deed.  Not any quicker to prepare than any other kind of deed.  Since it was a gift, her son gets her cost basis, rather than value at date of death.  If her cost basis was less than the $136K mortgage, that would be his cost basis (I think, I don't deal much with hillbilly probate).  

Did he quickly race to the appropriate government office to record the deed?  What fools these mortals be.