there is only one thing I would like to point out...
Taking pictures of children is, IMO, pretty much about getting in 'their world' so it would maybe have been good for you to bend your knees a bit and see the world from another kid's aspect...
Your model sure has the right expression and demeanor. The white background detracts from the crumbled asphalt and cracked foundation of the building. I might have had him sit down so you could eliminate the siding on the building.