Angela, what version of the game do you have?

From my understanding, which is very little, the earlier versions you had very little chance of getting them to go to bed. With the later version (.5) you have to tuck them in bed then quit the game for them to be well rested. Put them to bed when you go to bed, quit the game and go back to them the next morning. Encourage them to nap during the day. Also if they're exhausted for prolonged periods it may be best to get a doctors check on them to make sure there's nothing seriously wrong with them.

VF is they type of game that's meant to be played on a casual basis, as are the other LDW games, so far as I know.