If you don't want an abortion don't get one. There is always adoption or foster care.
Ultimately it is your decision, reguardless of your age an what she may have to say about it. This is your choice. Completely. Do not allow her to make this decision for you, or to pressure you into doing something you don't feel is right. If you decide to do this, make sure it is YOUR choice and not hers. If you decide to have the baby and choose adoption, make sure it is YOUR choice and not hers or anyone else whispering in your ears. And if you decide to keep the baby, know that you can do it! You can still do amazing things for this baby and for yourself. It will be hard of course as you are so young, but truthfully it is hard for everyone! No matter the age. Stay in school and do the best you can to be the best you can. My mother had me when she was sixteen, and she's always did her best. Always all that she could do and never anything less than! Growing up with my mother has given a very special bond and closeness that majority of my friends I had throughout school never had not will ever. You can do it.
Truth is, there will always be people who have things to say against your pregnancy, and people who feel otherwise. And at your age people feel intitled to say things and as if it is their business to do so. But it's not. And no matter what age you are people do these things because people are nasty. Do what YOU feel is best and forget those who disagree. You can do it if you want too, and you can be amazing!
Stay strong sweetie. Everything will be ok. Everyone isn't cut out to be a parent when they get pregnant,but adoption is ok. Your giving that baby a chance to have a better life than maybe we can provide. This baby is yours so don't let anyone make you do something you don't wanna do :) have courage