This A-Z I’m looking at aspects of medieval history that might be useful to writers. If you’re writing about young people in a medieval type setting, what might they have expected? We can say that there was some concept of children as something separate from adults, but that any childhood didn’t last nearly as long. By twelve or so, many young people would have been working, apprenticed, possibly married.
Childhood, such as it was, seems to have been a weird mixture of child appropriate things such as games and learning, with more adult appropriate things. Even those still deemed children would have been made to work with their parents before they matured enough to work alone. All of them would have drunk beer or wine (because the water was not safe. There was “small beer” specifically for this kind of day to day consumption).
Youth could also be a violent time. Parents generally didn’t hesitate to beat children. Indeed, it was considered a desirable thing by many, so that one key way of getting a young person to remember something was to give them a whack as you told them it, on the basis that pain was an aid to remembering. They were subject to adult courts, with any account for their age based on the personal feelings of the lord or priest judging them. There was only the most basic provision for orphans in many places.
The extent to which you want to reflect that is obviously down to you. Yet it always feels just a little odd when characters in fantasy novels with medieval settings have essentially modern childhoods, so it’s worth at least thinking about the balance there.