I know three guys who've gotten married to single moms in the last year and another guy is marrying one next month. I'm not sure what's more disturbing, that there's so many single moms or guys marrying a chick to take after a kid that's not theirs.
Lots of people seem to do it.
My girl has no kids and we aren't having any, and of course my kids live with my ex wife.
I've dated women with kids... Some dads stay around, and some disappear. My kids step-dad knows what's up and knows I'm always around.
Depends on the dad as to whether it's an issue.
Here's a hint, if the woman says my "baby daddy", run away as fast as possible.
If they say ex husband, then you're probably ok.