Hi, Mary!
The Disney Dining Plan "officially" states that a child must order from the Child's Menu when there is one available. (Read
HERE on page 2.) That said, your credits for Quick Service are only tracked as Quick Service, they are not separated by Adult/Child. The Quick Service Kid's Menus are great. They offer 2 sides, with a variety of choices usually including apple sauce, cookie, french fries, grapes, or carrots, so lots of choices!
Credits for Table Service ARE tracked for both Child and Adult, and you will see your remaining credits printed on your receipts.
I hope this helps! Have a great time in Walt Disney World!