Continuity mistake: When Toy Santa sits at the desk, objects on the desk change around between shots. Most noticeably, the reading glasses (which he picks up for a moment and sets them down) are at an angle, then turned so the lenses face the camera.
Other mistake: Charlie spray-paints graffiti on the wall of the gymnasium to protest Principal Newman's refusal to decorate the school for Christmas. We see "Newman" in large letters, an equal sign and a decorated Christmas tree with a big red circle and slash across it. The letters have sharp, smooth edges and the tree and ornaments are highly detailed. It is obvious the graffiti was painted with brushes, not spray paint.
Answer: They become widows, presumably, stop being "Mrs. Claus", and go back to living a normal life.
Phixius ★