Too bad. That's not the bus driver's job. The bus driver's job is to ... wait for it ... drive the bus.
If need be, the driver can pull over and call the cops if there is no driver's aide available, but can you imagine being the person who has to break up a fight between underage members of the opposite sex?
The worst fight, hands down, that I ever witnessed in person was between two girls when I was in high school. Nothing was off limits .... biting, scratching, hitting, kicking, ripping out hair (there were handfulls of hair on the ground), ripping off clothes. It took two coaches and a couple of football players assisting to get them apart and drag them to the principal’s office .... they were still trying to get at each other half way down the sidewalk. It was an ugly, ugly scene.