You can't make kids to eat so much fruits, even if they like them, especially in the morning.
Like an example. My kids never like to eat melons, but melons are high in essential vitamins and minerals. Vitamin C, A, Potassium and Lycopene plus they are always on sale at the grocery store. Guess who is putting melons into smoothies every morning now? :)
I usually clean melon, cut on 6-8 big pieces and keep in a big zip lock bag in the fridge.
So my morning smoothie contains any fruit or berries we have on hands. But most consistent ingredients are bananas and frozen berries.