I really hate reading these trope "talk behind someone's back" drama scenarios when it's just a person who made stuff up about the MC and spread rumors. To me, it's always seems like there's such an obvious and easy solution - just stand up for yourself, immediately ask others what some others about you, and clear up any misunderstandings. She could have stood up for herself by doing exactly what she did NOW all the way back when it all started in her old school.
But then again, I do realize that for many people, this is just something that's hard to do for them. I don't think there is actually anything wrong with this trope, but I've come to hate reading this situations because I've never seen things like this happen to me or the people I know - I've always just seen people immediately clear up misunderstandings or stand up for themselves instead of cowering away, so I when I see characters NOT do that and just blame and degrade themselves, it just makes me feel annoyed that the most obvious solution is not being used.