I agree it is not a great idea to involve a minor in this grow operation and I feel a little sorry for your mother because if you get caught it will undoubtedly affect her a lot with both of her sons in trouble. Why do you want to grow in the first place? If you have a decent dealer it is far less risky to buy some occasionally than to grow it yourself and while it might seem cheaper to grow, the costs soon mount up. Combine this with the paranoia of getting caught which will be ongoing for three months during the grow, maybe more, and the fact that presumably you are growing in a home owned/rented by someone other than yourself, therefore putting that person at risk too and it doesn't seem a great idea.
You read all the time of police vastly exaggerating the severity of grows (eg massively overestimating the 'street value' of the plants they have seized) and it might be worth doing a search of archives of state and local newspapers for articles on recent busts that have made the news to get a better idea of how police treat growers in your area.
Regardless of what you decide to do, I think you should be commended for at least thinking of such things in advance and I hope whatever you decide, it will be on the basis of having researched the issue. Coming on RIU and asking advice is fine, but at the end of the day, anyone can post and give you any information without having to back that up. You are far better to do the research yourself and make an informed decision based on reliable sources.