Most Helpful Girl
101 at 5'2 is on the rather thin side. According to the tables, up to 120 would be in thin side, maybe up to 130 if you have a bigger frame. Over 130ish might tend towards thick. Remember that muscle weighs more than the same amount of fat, so you can be fit and healthy and weigh more than a lighter girl who has more body fat. Also at 16, we haven't finished growing yet so our shape tends to change pretty quickly.
I hope at 101 lbs you're not dieting. Eat a heathy diet and don't worry about it.