Hi Robin,
I completely understand your concerns as I, myself, have a 13-year old son who is an extremely picky eater.
As your daughter will be 10-years old during your visit to the Walt Disney World Resort, technically she will be classed as an adult and should therefore really order from the adult menu.
According to Disney Dining, the official policy is that it is up to the discretion of the restaurant management as to whether or not a Guest can order from the children's menu.
That said, I can tell you that my family recently returned from a 2 week stay at the Walt Disney World Resort where we were not using the Disney Dining Plan and it was not a problem for my son to order from the children's menu at any of the dining locations that we ate at including lunch at
Be Our Guest Restaurant.
Wishing you a magical trip filled with memories which will last a lifetime!
Emma