Eaton Canyon has a great museum where the kids can look at animal displays, look at burned items salvaged when the previous museum was consumed in the canyon fire, play with puppets, etc. A really nice place for the kids. Also, the walks are easy, with plenty of river rocks for the kids to throw for hours. Would recommend bringing water and be very careful if it looks like a storm. You don't want to get caught if the water level rises.
Pros: easy hike, oak grove