Sucks but that's the way it is. How did you get together with her? If you flirted and eventually asked her out, you're already doing things that most people with AS would be terrified to do. So it's not like you're on the low-functioning end of the spectrum. You sound like a reasonable guy; her family members are probably avid readers of Stormfront and would throw out any guy that's doesn't fit the Aryan phenotype.
Besides that, you're 18. I'm sure you weren't thinking of having kids yet, and if the girl was (until her family shot you down), she's delusional.
AS is highly hereditary, highly dominant, and usually y-linked. In other words, if you and your wife have a boy, there's a huge, huge chance he'll have AS as well.