being a teen mom is not easy .. because some bodies are not in good development to have a baby, I'm 16 years old, this is my first baby girl will have a great because I always wanted to have a mini me .. but first of all I wonder how my body was goin to be left after having my princess and how I should take care to avoid being spotted and streaked etc. ..
As said before, genetics play a huge role. But eat healthy, and stay active. That will help ensure you're only gaining what you need to gain. Also, breastfeeding can help women lose the extra weight. Good luck.