Welcome to Librarium Online!
Big ups for young first time painter, not bad for a first attempt.
"Courage without the presence of fear is like a pistol without bullets. Meaningless." Colonel Igor Massif, 6777th Severite Rifles M40
I'm not going to lie, I looked at the pictures before I read the team name and I thought you had just painted a halfling in a Tigger suit. The thought of that made me honestly start laughing out loud.
Looks VERY cool. the one suggestion I would make to your brother is to try the washes on them. The helmet at least looks a bit more shiny than a BB veteran's should!
http://www.armyroster.com Check out my ToP WIP in the projects section!
As a first model for a 12yr old its amazing! When I was 12 painting consisted of a tub of paint, a marine and a big dunk! I'm sure as time goes on he'll improve loads! Great start!