One year around St. Patrick's Day, the children were showed the pictures of their Irish ancestors. When Dad wouldn't let the kids take the original pictures to school, my daughter asked if she could draw their picture. Take Vacations Genealogists love to take research vacations. While genealogical vacations are difficult with a spouse, they are even more problematic with small children. See if there are any historical spots near where you will be doing research.
Children can also look at tombstones, noticing the different types of stones and engravings.
Care should be taken with small children at cemeteries, however. Old stones, on unstable mountings, have been known to topple and in at least one instance a child was killed by a tombstone as it fell to the ground. Signatures Children love to write their name. Make copies for the kids to look at. You can even discuss how the ancestor made his or her letters.