Nah sell it and get a PS2 instead. LOTS more selection
Games for those ages are hard to come by on the Xbox. It's geared for the "mature" (what an oxymoron) gamer. Shrek 2, Finding Nemo, Incredibles, Barbie Horse Racing Adventures, Spongebob may be a good fit. Check out
http://www.gamerankings.com before you buy the game to read up on the reviews. There are a few platformers but nowhere near the family type games the Gamecube and PS2 have.