Now that I got that obvious opinion out of the way...let's get down to some serious problem-solving. She lied to you, pure and simple. I don't like women who lie and I bet you don't either. Next, she's underage...there's no getting around that fact. You are in a heap of s**t if this fact gets out. What will her folks say? What will your folks say? What will the authorities say? I'm going to be quite honest with you, I know exactly what you mean when you say that she looked and acted 20. That discussion is for another time, but damnit, it's tough to tell sometimes and if she lies to you, well, what's a guy to do? Any way, if you can provide for the child in a manner you suggest, I'd part company with the mother but handle child support that way. You don't want this awkward situation over your head the rest of your life. Her life will now be on hold and stuck at age 17 for about the next 18 years. You want that kind of immaturity for a wife on top of being a liar? No, you don't. A marriage of this caliber is doomed for failure. It's an automatic divorce in a few. Play politics. Make nice with her because she's got you by the balls, and try to get out as best you can. Maybe she'll bite on that bait and let you pay your way out. If she goes for that deal...TAKE IT, MOVE OUT OF TOWN, get your life back together and consider yourself a lucky man. If she takes the adoption route (which I highly suggest), please push that option. Never suggest abortion...the little baby had nothing to do with this screw-up, why should she pay the ultimate price?
IF SHE TAKES NEITHER, oh boy, then you need to gather all the troops around and calmly find a solution. Remember, the more she sees you calm and normal, the more she won't act nuts and cause problems. Girls at this age are unpredictable. The law doesn't give a crap that she lied to you. Probably nine out of ten on this 'Zone understand that you were honestly duped...but we don't count when a district judge and eager prosecutor are gunning for you. Consult an attorney, on the side, as soon as you get off this board. Pay some money for expert advice. Cover all the bases...just in case. You wanted honesty!