Jesus Christ. The replies in here seem focused to make you more anxious. They also seem to be running away with your fears (some of which shouldn't be fears) and everyone's become paranoid to the extremest degree. First up:
Foetal Alcohol Syndrome can ONLY occur in women who have a predisposition to the syndrome. Someone who possesses this genetic marker is NOT the norm. You have to have the genetic template for FAC to actually give birth to a child that possesses FAC - and women who possess this genetic marker are in the VAST minority. That is: the majority of women who drink during pregnancy will NOT give birth to a child with FAC. Women avoid alcohol during pregnancy because there is no test to see if the child has FAC. Ergo, women will avoid alcohol on the off-chance they have the genetic markers for FAC. We have thousands of years of births occurring while the mother was still imbibing alcohol: and while this isn't ideal (while a modern-day mother should put the needs of her child ahead of her own behaviour, it is only the fact that we now understand what this syndrome is that is driving protective behaviour rather than "this syndrome is now public knowledge ergo it happens to everyone!" - FAC has always been around, but we're just now publicly acknowledging it) it indicates that there is a HIGH chance that your child is fine. That is, there's a VERY good chance that the child will be born without any disorder whatsoever. As a child that shouldn't have been born into this world, I can tell you that sometimes life trumps one's best intentions and the child comes out "normal". So you should put that concern to bed, and remind yourself that it's just the panic talking here. And I DO get why you're panicked, but the responses here aren't going to help you in this panic. It's not as bad as you think and your life is FAR from over.
On the other hand, I get that you are clearly and understandably panicked by this. You didn't ask for the kid, and now someone's having it on your behalf. On the upside, the laws "favouring" mother-ownership of the kid is in your favour here. SHE will raise the child and you are NOT responsible for being involved with it. This is the awesome side of the mother choosing to have the child or not: it's her responsibility, not yours. You have no legal responsibility to the child, IF there is a child (more on that below). You seem like you're appropriately anxious about this, which speaks well of your character. But that doesn't mean you should feel so guilty about this that it affects you to the extent that it's currently affecting you. The truth is that if she decides to have the child, that's on her. You do NOT have to feel responsible or anguished or to blame in any way (legally or morally). She's the one having the child and she was the one who was irresponsible enough to ignore the fact that she's pregnant.
OK, this girl sounds crazy and she sounds like a liar. You have no responsibility - NONE - towards her. IF she has a child (and the liar part of her personality gives me pause on this one) you don't have any moral responsibility towards her. NONE. This would the same if she was an abusive nasty wife. Her actions since you both parted ways aren't your responsibility.
I'm a bit worried that you seem all alone in this situation. If I, a stranger who is not from this sub, can feel anxious for you - wouldn't your parents and friends support you through this one? I would speak to someone you know - hell, maybe just show you them what you wrote here? I think they could see that you're genuinely upset about this, and they'll help you. Seriously. I can understand that you're anxious... I'm giving you the "wake up to yourself, it's not as bad as you think! Think about it more clearly!" speech because I think this is all driving you to a point of anxiety that's insufferable. Which you don't deserve. You need a clear head here: and a clear head tells me that you'll be OK. You just need to realize that the child is HER decision and you don't need to do anything you don't want to do. Seriously. Your anxiety about this situation isn't fair, but it DOES tell everyone you're essentially a good person stuck in a troubling situation. It will pass, and it will pass more quickly than you think.
Good luck and if you need an ear, IM me.