Yes, most places do have children's menus.

However, your junior child (the 11 year old) might have to order off of the adult menus (but sometimes CMs are understanding and will allow your junior to order off of the children's menu...as it is technically for ages 3-9 only). If you search on
http://www.wdwinfo.com/wdwinfo/dining/disneydining.cfm, you will be able to find the menus of the restaurants that you are interested in, to include their children's menus.
Bon appetit!