Not only is this teacher educating her children in violence, she also has to continuously escalate her own violence to keep control. Her method of teaching breeds disrespect and prejudice. Her students have been dehumanized.
When people are forced to respect civil rights and human rights or face legal consequences, they don't like it. Civil rights laws will be scrupulously observed only when people accept that it is morally wrong to oppress or discriminate against fellow human beings. That awareness can come only through education. A law will enable integration in public places, but it does not foster understanding or appreciation in the hearts of people who continue to live with their prejudices.