The best thing I can tell you is that kids don't want to do the same old thing time after time. That's why at our school they have "traditional days" where we work on katas and our punches, kicks, stances, blocks, etc. They also have sparring days. Basically, from kids to adults (depending on what class) you strap on your sparring gear and get after it. Naturally with the lower belts, you're usually working on certain kicks, punches, blocks or counters when you spar. However, the higher ranks get it on. Maybe you can take the same approach and work on some things on certain days and mix it up for the other days. ***NOTE*** I am NOT saying to have your 11 year old beat up on the others! Just maybe work on kicks one day, stances another, etc.