Add the lemon zest, lemon juice, sugar, salt, and water to a 1 - 2-quart-size microwave-safe dish. Microwave at full power for 3 - 4 minutes, until the mixture begins to boil.
Stir in the couscous, cover, and let stand for 5 minutes. Fluff with a fork. Transfer half to another dish.
Stir the green onions and parsley into half of the couscous. Season with salt and pepper.
Stir the butter into the children's servings until melted; fold in the mint. Season with salt if desired.