Middle grade book where the popular girl's house burns down at the end

This would be a middle-grade to potentially YA book. Not sure when it was published, but I read it in 6th grade, 2016/17, in Ontario. I think I got it from my school library. Paperback, not super long, cover had shoes on it - one set of shoes was nice/fancy/'trendy' dress shoes and the other was converse, I believe.

The story was written in 1st person and has two perspectives. One perspective was the quiet, shy, nerdy, bullied girl (girl 1, may have been named Ruth?). The other perspective was a popular, trendy, rich girl (girl 2) who was in some way involved in the bullying of girl 1 (either directly bullying or in that social circle). Girl 2 *may* have been named Talia? They go to the same middle school but know very little about each others' lives at the beginning.

Girl 1 ends up in some sort of English/writing or art class, and starts to confide in the teacher of that class about what she's experiencing being bullied. I think it was English more likely because I remember poetry being involved and her being a good poet/possibly having a poem entered into a competition of some variety.

Girl 2 is relatively rich and wealthy but does not have a close relationship with her parents due to them being gone/working most of the time. She has some sort of nanny/housekeeper situation who she does have a relationship with who is more of a parental figure. She has everything she could want object wise but does not have many close friends (all of her friendships are shallow and based around her popularity) even though she seems popular.
The book ends with her discovering accidentally that her wealth comes from some kind of fraudulent scheme, I think police are involved, and at the end, her house burns down (I think I remember that being to cover up evidence of some sort but I'm not certain about that).

The book ends in the perspective of girl 2, who is describing/thinking about how she has nothing except for what is left in her locker. Her family is moving away, to another town with a much smaller house, and she expects to be able to spend more time with her parents. She has a conversation with someone where she expresses that she is looking forward to starting fresh as a new person, and that the only one she will really miss is her nanny. Girl 2 apologizes to girl 1 before she leaves as one of the things she needs to do before she moves out.

Thanks in advance!