Do you take her on walks or do any kind of training sessions? Although you listed forms of activity they were really forms of activity that will not really get their energy out except playing fetch. Running around the house nipping at a child will not get energy out one bit. It actually does the opposite and over stimulates them to make them go even crazier. Overstimulation in animals is a pretty common reason for bad behavior. To get their energy out you need to be having her perform a task that actually uses their brain power too. Just letting them go wild in the backyard or running around the house isn't performing a task. Walking on leash is a task because she has rules, she has to listen, and is on a mission of sorts.

You paid for a boarding school, but really unless you are continuing to teach the same things in the same way they taught, then it is kind of a waste of money. They can't just learn once and remember it their whole life. Dogs need consistency and constant training otherwise it goes right outside the window especially when so young. They can be high energy, but high energy doesn't mean they shouldn't listen and run wild. High energy dogs when trained properly know when it is appropriate to use their energy and when it is time to listen. Listening and following commands can just as useful as a tool as physical activity to get energy out.