How much pressure do you think a person could take? She already has to get the top grades in her class or she'll become a disgrace to her father. And if he ever heard of the trouble She got into with Harry and Ron, she'd never hear the end of it. And also with having to try to live up to her sister's legacy of being the perfect student, valivictorian, involved in all the school events, andstill able to be the most popular girl in school with the best boyfriend and the best everything, she just couldn't take it. Hermione was on the verge of snapping.
and that's what happened that one Saturday morning when she did something that caused her everything she had worked so hard for and landing her a month's detention. Of course it wasn't completely her fault, but nobody would listen. So of course Hermione was upset about it. But what hurt her the most was the way her father reacted. he could have just said he was disowning her, and she still wouldn't have felt as miserable as she did then. But never mind that. That all didn't matter now, because she was going to get back at them. In a way they would have never imagined.