Adoption 100%, Abortion, do not go there friend. Trust this from someone who many years ago allowed his 16 year old girlfriend to be pressured into one by her older sister and mother. The guilt and shame never leaves you, and you feel sooooooo bad when ever you hear the word. I was blessed to find God 10 years ago and so did this girlfriend who is now my wife. We both finally feel forgiven but still remember the horrible mistake we made. I should have stood up and refused it to happen but I was afraid my parents would find out. Friend I plead with you do not let or pressure this girl to terminate this child you will regret that decission the rest of your life, let this child be born and go to a loving family.
I now have been totally blessed by God, He has given my wife and me 4 beautiful, intelligent girls who all love Him and their parents very much. As this child may not even be yours please do not pressure her as it would not be yours to have an opinion. Do the right thing and support this girl, if you find out that this child is not yours then I guess you will get the freedom you want.