Lots of family sitcoms have been based in New York City, though; The Cosby Show was set in NYC, wasn’t it? All in the Family was set in Queens.
So in fact, “Nesting in the City” is pretty old hat.
Emilee, it may well be a regional thing. I grew up in the South, and folks here seem to settle down earlier than folks in the Northeast. The people I know tend to delay having kids until they’ve finished grad school, but it’s very common for people to get or be married in grad school or right out of college. Housing prices also tend to be more reasonable down here, so it’s easier for a young couple to buy a home.