If your male ancestor died and his wife survived him, have you fully traced what happened to his widow after his death? Was she willed property that would pass to his heirs after his death? There might be a record of that land transfer after she died. Did she remarry? There may be mention of a previous husband when she does. She may have died under another name and left records under that name–perhaps one that mention her children by her first marriage.
Did she pay property taxes after her husband’s death? Those records might help you to estimate when she died if there are no death records and she left no probate.
There’s also the chance that there is no record of her after her husband’s death.
But you won’t know until you look.