I actually said, "OH, Sh!t" out loud when I read that post.
but i all seriousness this is gonna get messy...
My $0.02: a girl with kid(s) (and an inevitable ex-husband/baby-daddy), is not for the faint of heart. If you both love eachother, you'll be able to figure out this mess, particularly the custody business... and all the hardship to get there will be worth it...
Had a similar experience myself recently (the price I pay for having a taste in older women) although we admittedly did not get to the point where dealing with the custody of kids post-college became an issue, didn't end too well for me, although that relationship ended for non-kid-related issues...
But I still echo the sentiments of the above posts...
Don't do it just yet!!