How do I get this girl to consider adoption? Even if it's best for the kid?

if she says no then it is a no. in the mean time, do not go to the hospital when the kid is born, do not sign anything acknowledging you being the father, do not let her know where you live/work. change your phone number and address if nessesary. they can not make you start paying child support until they serve you with the papers so happy hiding. once they catch up with you (and they will) tell the court she told you it wasn't yours so you stepped aside but now that you know you want to do right by the kid and file for custody/visitation. the higher the % of time you spend with them the less you have to pay. i'm sorry you got caught in this money grubbers trap (but hey maybe the DNA test will clear you when you go to court ask for one just in case). best of luck