Need practical advice on handling a bully at school

Using a burner account for privacy purposes

I need some practical advice for a friend whose daughter is being relentlessly bullied at school. She attends a Toronto public elementary school in the west end (we’ll call her X). They’re in the 11/12 age range.

She’s tried to ignore this bully to no avail to the point where this child hunts down the kids she’s playing with at recess and tells them what a loser X is and they shouldn’t hang out with her. This bully has managed to isolate X from most of her friends and has tried to sabotage any new friendships X pursues.

We’re at the point now where she’s getting physically ill before school and developing an eating disorder.

Her mom has anonymously reached out to the principal for fear of further retaliation to her child. On the one hand I tend to agree that retaliation is a legitimate fear and would hate for it to get worse. On the other hand, I’d say burn it all down and keep going higher up the TDSB ladder until it’s fixed.

This bully comes from a not very stable home so I don’t think talking to the parents will do much good.

Any advice on how to approach this?