it isnt that hard to do a hidden grow at a young age from your parents, i am sixteen and my plants are doing lovely, i have done many concealed grows indoors LOL, and it is that bad of a thing to do, if you get caught then you will get a warning from the police, nothing any worse than that, and then make sure you DONT EVER GET CAUGHT AGAIN OTHERWISE BAD THINGS WILL HAPPEN(like jail) and don't slate him for growing without his parents consent.

good luck man keep us updated, when the plant gets bigger i think you will need more lights.