Mom of two who lives in an apartment here, my oldest knows she's not allowed to jump or run around unless we are outside. My 1 year old doesn't really understand this concept but we try to tame the wild out of her anyways. Once kids reach the age of 2-3 years old they can easily be taught about respect for neighbors.

We actually live underneath a single guy in his 50s...he works out above us and runs in place in one particular spot every day, he also drops his weights on the floor like he's at the gym. So while I understand that kids are usually pretty loud, sometimes adults are pretty damn loud too, and I think it's worse with them because they KNOW better but do it anyways.

What shocks me about your situation is that the mom actually said "hope you like noise" totally unapologetically. That's incredibly rude and inconsiderate for you.

As far as adult only apartments go, I'm not sure if that would be easy to enforce without basically retracting pregnancy as a discriminated disability status. In your situation I'd recommend the top floor or a townhouse style apartment. You're only option here is to move. You won't really have a case if you complain about them using their apartment as children...as annoying as I'm sure these ones are.