Try looking at Dr. Bronner's. Their products are all natural and are really good on sensitive skin. Also, they're not very expensive.
What is the best sensitive skin body wash?
My daughter's age is 11 and her skin is very sensitive. She uses Gentle Skin Cleanser and Calming Moisturizer from Kidskin. Kidskin is one of the best online skin care line for kids and pre-teens in my point of view.