I'm really not a fan of when they try to make the bully the friend, especially in this case. This girl led a bullying campaign that was cruel and manipulative for the most petty of reasons, for an extended period of time. I just don't want her in this story, and I feel pretty sure that future chapters are going to make her a friend after an incredibly minor redemption, if anything (would love to be proven wrong though).
In these iyashikei some characters gotta be healed, and others gotta GO, and she, my friends, is the latter. Let's (fruitlessly) hope...