It appears that this transaction may involve Mary Robinson Chastain, who married John Chastain (1743-1805) in 1798 and bore his three youngest children - Violet, William and Mary. This John's will did give land to his widow, Mary, and it was to go to his youngest son, William, upon her marriage or death. He had an older son, John Junior in about 1766 by his first wife Mary O'Bryan. If this is anyone's line, I have a scanned copy of the renunciation statement that I will share.