Depending on their size, the instructor may have to handle all of the ground operations as they may not be able to reach the pedals.
As the kids start to get older, I think that actual flight lessons on the control of the aircraft in flight can be great. These types of lessons should only be done on days with excellent weather conditions. The goal is not to teach them everything that there is to know about flying but to give them confidence in their ability to handle the airplane in flight. Depending on their size, the instructor may have to handle all of the ground operations as they may not be able to reach the pedals.