That's the difference between "story" and "HIstory". History should be remembered. But of course the more accurate it has to be described, the less feasible it is to record and observe all of that. And that's not for children to do, but for historians. Children should learn essential parts from history, though. Maybe some age-appropriate stories are good for that. Of course, children are the future and so we should make them able to imagine a better world, a more inclusive one with lesser (or ideally without any) non-harmful boundaries. So yes, let anyone being able to dream of becoming a princess or a frog or whatever he/she/anything wants to be.