For eight years old, that is actually very good. Especially for what you're given in stock media!
Really show him how lightmapping can help add to the environment and mood of the levels, and perhaps try and get him to purchase the full FPSC with one or two model packs to add to his inventory, and I believe that he has a lot potential with this! No joke.
Well, all I can say is great job man, keep it up!
(P.S. Let him know the FPSC community is fantastic, and there are countless people on these forums that contribute so much for everyone. Hint, there is tons of free entities, models, mods, etc. that he can get for free thanks to those who've contributed them)