It is because she is rarely left with other children without one of her parents nearby that we are able to watch for certain behaviors and nip them in the bud.
What I didn't make clear is that school settings lead to this “sorting out” and are harmful to both those being picked on and those who are doing the bullying. It is a parent's responsibility to cultivate a respect for others by training their children and being honest about their little darling's sinful nature.
You sound like great parents! Keep up the great work!