A basic but often over looked area when building your preparedness kit is to have items to keep the kids entertained and occupied.
Having them pack a an electronic gaming device like a Game Boy or Nintendo DS, or even an ipod are great ways to keep them entertained. Make sure you have battery backups, a solar or wind up charging device to keep them powered.
Another great way is pack some of your favorite board games, great not just for the kids but the entire family and will help to pass some time if you are waiting something out while sheltering in place. It also presents a way to make friends at your community shelter if you must go there.
Giving them pens, pencils or even crayons and blank paper can be useful as well.
As a last resort you can always share stories and story telling to pass the time, another great way to learn about one another or a new group of people.
Again, this is not the most important item in a survival kit, but if you have kids an excellent idea.