I remember “girls’” bikes, from my childhood, basically a regular bike with the central frame thinger removed, so they could be used by riders in long skirts. Do they still exist? I know those big skirts are pretty rare any more, but I am not up on childrens’ bikelore.
Back in the century I come from, a girl’s bike, like anything girly, was an object of derision. It was okay for a girl to ride one, because she was only a girl. But woe unto the boy who sat on one, even briefly. It doesn’t matter if he popped a righteous wheelie and then stole the bike; he was infected with cooties, and probably a sissy.
Nobody had to teach the kids. We all knew.