What age did kids in ancient egypt start working?

Up until the last sixty years or so, kids worked (at least part of the time) from the time they were old enough to do simple chores up until they left home to start their own families. Prior to the early 1900's, it was common for children whose parents could not afford to send them to school to work to help support themselves and the family.

Only in the past half century have we managed to produce a leisure class of children, and it has not done either them or society a bit of good.