At a counter service restaurant one or two people go up and order the meals for your party, while the others in your group snag a table. At this time the kids meal credits are grouped with the adult credits. So on our trip, unless my DD saw something on the kids menu that she liked (the selection for kids is dismal IMO and the food is always ice cold) she would share with me or order something off of the regular menu, we never had a problem doing this.
She is not a big eater, so the kids meals were the perfect size for her, but they were not appetizing. They are prepacked and served cold, we tryed them at several counter service locations, and each time, no matter what, they were cold. So a few days into our trip we just stopped ordering them.