If the kids are under 13 you should talk to your caterer about having kids’ meals made. Young children will probably not enjoy what the adults are eating and why should you pay $100+ for each child to not eat their food.
Many caterers offer chicken fingers and fries, pasta with butter or marinara, mac n cheese and other kid-friendly dishes at a fraction of the cost of an adult meal.
Give your caterer a head count of how many kids are coming and decide with him if you should offer more than one option. It may or may not effect the price.
Cocktail hours usually offer enough of a variety so you don’t have to plan a special kids’ menu for it.