Medieval society kept noble children and common children strictly apart except in one place: the monastery. There, rich and poor children alike could be dedicated to God from a young age. Until the Fourth Lateran Council of 1215, children as young as 8 could be placed in monasteries to grow up and later take orders. This happened with both boys and girls. These children were called “oblates.”
Why would parents do this? In some cases, the child herself felt a vocation and asked to go to the convent or monastery instead of preparing for a secular job or marriage. In other cases, one of the parents had made a vow during sickness or danger that if they lived, they’d dedicate a child to God. Sometimes, poverty made the family glad to have one less mouth to feed. Other times, the family (especially if aristocratic) felt a need to win favor to expiate sins of violence. Finally, it was a way to have a child educated.
Many of the most famous medieval saints had been oblates and knew no other way of life. Of course, though, it didn’t always work out. Some oblates were clearly not suited for adult monastic life and had to be sent away. Others ran away, while others took orders anyway, having no other options, and were troublesome monks or nuns who brought the world’s sins into the cloister.
For most oblates, it would have been a gentle, kindly way of life as long as they didn’t mind waking up at odd hours for prayers. Nobody in the cloister slept through the night. But apart from that, monks and nuns would have been kind foster parents. Meals were regular and life was quiet.