Mary and Winslow were happily married. They loved children and turned their home into a toy store, Schott Toys. They wanted children of their own but it wasn’t possible.
One night, Mary was killed by a car during a snowstorm. This was the beginning of Winslow’s downfall, not having Mary to keep him grounded.
It was revealed that there was never a record of Winslow being married. It turns out that Mary was a life-like robot that Winslow had created.