@ASDFGHJKL
I assume this is a setting in korea, so it's likely they generally preffered her brother simply because he was a male.
Also if her brother was naturally smart, and she had to work really hard to get his average grade. It would often be very demotivating and likely only made her give up faster if it felt hopeless.
this is coming from someone who is a sibling themselves and often had bad grades lol, my grades are better then my brothers now but I have to study almost 5 times as much as they do in terms of actual hours. Mostly started working hard to get into a good university and not because i'm directly competiting with them, getting compared is usually more demotivating than motivating lol.
