Britster, I know you are an excellent mommy to Jackson so this is no way directed toward you.
I do understand though why rescues would be discouraged at the thought of giving a dog to someone as young as you. I think most people in their late teens and early twenties will experience major changes over the next 5-6 years. Plans change, people get married, some move, or go off to college and sometimes a dog doesnt fit into the new plan.
I had NO intention of getting married at 20 and moving to Johnson City to live in an apt with my high school sweetie. But I did. I know there are the exceptions, a few young members here are excellent furparents. But when placing a dog that may have already come from an unstable situation, a rescuer has to ask themselves is it worth the risk.