I take Metagenics Ultra Clear Plus Ph. I am sure they make a kids product. My Integrative Specialist (trained MD also trained in Holistic Medicine) recommends this for my Fibromyalgia.
http://www.metagenics.com/products/a-z-products-list/Ultr...
I also have to eat GF/CF and their products work well for me.
For probiotics I give my kids (ages 5 and 3) Animal Parade AcidophiKidz. It's a chewable. I used to give them the Infant's Probiotics powder from Udo's choice when they were younger. Just put it right into their juice. If you are doing the metagenics shake, you can put it right in it.
For vitamins and Fatty Essential Oils, I give my kids Yummy Bears products. My daughter also has to eat GF, so I know for sure that their products are GF/CF. They love it because they think they are eating regular gummi bears :).