@squishles on a feudal society(on our world at least) a horse had more political power that a woman, if a woman was not married at 7 or less, she probably had no political use and had no one to look over her, so anyone can take possession of a woman like that, even if its a noble, usually only the 5 first daughters had any political value, and people had like 20 children back on feudal times, the name dark age is pretty accurate to describe those ignorant times back on the 5th century.
This world on the manga is pretty modern, specially because of the school accepting woman, woman used to be forbidden to attend school, any school, forbidden to learn how to read, they had no voice or will, that is how bad feudal society treated woman.
I don't think this world is Feudal, it is post Enlightenment at best, comparable to our world 17th/18th century.