There should be no kids in cities as a rule, in general, as cities are for higher education or work, neither of which kids are capable of and should not expect to adjust for.

Crazy enough there are no cities with only adults to prove that such a city would be a paradise for adults.

Imagine a gigantic campus or company, everyone at a similar mental capacity and life experience, present to expand their thinking, not to be disturbed or distracted by other people's inability to raise their children properly.

The only reason kids are in the city is because women are expected to join the workforce to earn money.