I dont reccomend a turtle for a 10 yr old.
Ornate wood turtles requirements are HIGH and expensive as are ALL TURTLES.
You need a large tank, 75 gal or bigger, the ability to keep the humidity high, feed fresh food not commercial food..including LIVE earth worms, and other bugs. Plus a water tub with gets dirty quickly...even WITH filters.

I dont think a turtle is good for a 10yr old. (my son is 10...he wouldnt.)

Maybe a small rodent, rats are fantastic. they dont smell, come when called and are easier to feed and care for.