When working with parents, we have no age limit for some jobs (and assume children will be supervised closely by parents). Children 14 and over can work on other jobs. At 16, they can work with approval of all crew members working that day, to work under close supervision of a parent or other crewmember, and begin gathering signatures toward the on-hands training we do. Of course, for working on crew, attending Safety Weekend, or doing the make-up videos and related materials goes for them, too, for crew work.
For a 10 year old and dad, we could find a job, just not on crew. There is lots of other work around the place. Let us know when you want to be there and how much time you have.
That goes for anyone else. We usually find a way to get a train ride of some kind if it is important to the volunteers. Last time we had new guys that finished the project they were working on, they learned how a ballast train works, and that our enthusiasm when things go well sometimes causes us to skip lunch. Of course, there were no children in that group, and we did give them the option of being dropped off near town for lunch. We're alway flexible. We're volunteers!
Cindy