Movie question?

can't remember a movie from a long time ago, so obviously its a kids movie, if that helps. um, it starts out with a mom and her son moving off of an army base because her husband (obviously in the army) is missing or presumed dead or something and they go to live in her family's home. the boy somehow ends up in some other world, where a a prince's evil stepmother has him locked away. also, when the former queen died, her subject cried so much it created a lake. then i only remember then end, where it's christmas and the boy's father returns home and the step-mother is tied to a chair with ugly hair and forced to look at mirrors all day. please tell me the name of this movie if you can.