The wife/mother actually is not an active character in the book. She had killed herself because the world was dead and she refused to wait until bad people showed up to do unspeakable things to her and her family. She wanted to kill the boy as well but father refused. One always wonders if mother represented sanity and father represented futile hope. The world was dead: it's rotting carcass supporting the remnants of diseased humanity haunting its dead landscape.