Le Cellier offers a 6oz Grilled Steak for children. Coral Reef offers children a grilled chicken breast (not nuggets). Chefs de France offers a fried fish plate for children. Rose and Crown has cottage pie, bangers and mash, fish and chips, and grilled chicken on their child menu. Teppanyaki offers a small stir fry with either chicken or shrimp. Nine Dragons offers sweet and sour chicken. San Angel Inn offers children either a burrito or an enchilada. Marrakesh offers couscous. Spoodles offers Grilled Strip Steak and Grilled Chicken. Flying fish offers fish and chips, grilled steak, chicken breast (again, not nuggets).
I'm pretty thoroughly shocked to see so many choices available for children. Choose your restaurants wisely, and your child will be more than pleased.