Listen to Weedhound, This is some very very good advice. You have to trust her or it will never work. Weed, you could be a counselor. I might need some help too.
The child may not be yours but that doesn't mean you can not raise her like your own. The child is the victum here BUT you have to be sure about your girlfriend. The military is an awsome responsibilty in itself ( God bless you and keep you safe). I'm an old military brat. You can offer her many things an average Joe can not. I hope she is not just using you. You must be sure and make sure this doesn't effect your job.

30 years with my highshcool girlfriend and since I got popped for growing last year. She doesn't trust me and things have not been the same. I have never been in trouble before. Reading this, I think we wil go to counseling for sure.

Peace and God be with you. I hope you make the right choice.