marriage or not?

I’ve known this girl for a very short time and I got her pregnant. Don’t ask me how, we all know about the birds and the bees. Some background, she was a stripper when I met her, soon after she quit her job and makes 30% of what she used to make with a regular job. So far I’ve met 2 exboyfriends, and her child’s father and child (really cool kid) and heard many stories about how she was….promiscuous. She’s also been through every kind of abusive relationship known to woman. She has 3 outstanding traffic tickets, has no credit, and her car has illegal tags. Being military and cornered, not only by the military but by her, should I marry her to be able to pay for the medical bills and recieve an extra 1200$ for housing and food and what not? I don’t think I have a choice. If I do marry her what are my options in terms of prenumps or….is there any way I can secure somehow my future and my assets? What should I do if when the baby is born and it’s not mine? How viable is a divorce then?