I'm not sure how lots are 'tagged' so specific sims show up (like no kids at night clubs/bars). With the advent of toddlers, more and more lots are being made toddler friendly. I have a couple parks in particular with toddler play areas and even training potties. Toddlers don't show up, though I CAN take my family toddlers along.
In TS3, parents often took their toddlers to community lots like the parks (it was fun to see parents teaching their little ones to walk in public). I'd love some kind of visible lot flag or even a lot trait that could be added to allow toddlers not in my household to show up on toddler friendly community lots. I'm not even sure it's possible but it sure would be awesome.