I would calculate the dose by body weight. How many drops to a tablespoon = adult dose (approx 150lbs?). Then weigh your child and give amount of drops. When you calculate how many drops per lb body weight, please post for others here on the forum. Also, put drops into small amount of tepid (not hot) water to evaporate the alcohol.
I dont think you're supposed to do a maintenance dose with kids. Just dose twice a year.