Not only is family participation good for the dog, it is also great for children. It teaches children that dogs are not stuffed animals and they need to be left alone at times. It also teaches them patience. They cannot all work with the dog at the same time.
When I am training a whole family, I have the children take turns going first. They are very excited to show me how well their dog is doing on my return visits! Remember, always play with your dog when he is done working for you!