I weigh 125lbs, 5'2 and I am 16
Is this a good weight for me?
If not, what can I do?

What is your body frame? Small, medium, or large? That makes a difference.

Here is a website that explains the frame size and how to measure and also the weight charts.

Body frame size? Small frame, medium frame, large frame?. (http://www.am-i-fat.com/body_frame_size.html)

I weigh 125lbs, 5'2 and I am 16
Is this a good weight for me?
If not, what can I do?
There's a lot more to it then just height and weight, it takes activity level and body frame before we can tell the average.;)