I can tell you exactly how many kids live in Staatsburg as of the 2010 census (indulge me for a moment here): 24.6% under 18 x 377 total residents = 93 kids. That's not really a lot but the good news is that I do, in fact, know people from Staatsburg, and all those people seemed to be pretty close-knit with one another from childhood up through high school and beyond.
I'm sure that if you've got neighbors with whom you're friendly, your kids will be able to find long-lasting friends up in Staatsburg, despite the fact that the child population is pretty low.