So i know this is kinda a strange topic to think about, but it's pretty clear that even though Gekko and Armadylan are the ones with super strength, everyones a lot more durable than the average kid.
Owlette was flung into a poll by Robot and landed straight on her stomach. The impact would easily break the ribs of a normal five year old, but she got up just fine.
The Ninjalinos were flung from the top of Mystery Mountain all the way down back to Earth! Not to mention they landed in water, which should've hurt them even more and they looked fine.
And pretty much everyone in this show has been launched into the air and fell from a pretty big height, crashed into metal and again, got up to see another day. Does having superpowers grant your bones strength? Sure seems like it!