Fighting Back

In the three years my daughters have been in preschool, they have rarely been sent to time out. In fact, I can only think of two instances and it was the same daughter.
Last year, Sue Sue received a time out, along with a few other students (none of my other daughters), because they refused to come in from recess. They kept playing. The teacher gave them a warning. Then she made them sit in time out the next day during part of recess. Sue Sue also lost some privileges at home. 
Last week Sue Sue received her second ever time out at school. I guess I should be upset, but mainly, I'm delighted. You may remember a few months ago when I wrote a post about "Becky." Becky is a little girl in preschool who causes problems. On a regular basis, I hear tales of Becky's wrongdoings. Becky pushed Tortilla. Becky took toys from Cakes. Becky yelled in Sue Sue's ear. Becky bit Roo. So what do my girls do in return? Nothing. After the biting incident, I reached a decision. Since Becky has continued to be aggressive toward my girls (and pretty much every child in the class), I instructed my girls to fight back. If Becky pushes you, you push her. If she hits you, you hit her. Normally I wouldn't condone this, but the teacher clearly doesn't have a handle on Becky. When I expressed concern, her answer was "I'm working on it." I could be that mom and call the principal, but I wanted to see what happened if my daughters tried to take care of themselves.
Sue Sue's time out? Becky pushed her. Sue Sue pushed her back. They both went to time out. Sue Sue was not the one to tell me about her time out. Neither was the teacher. It was her sisters. I sat Sue Sue down, asked her why she went to time out. "Because I pushed Becky." "Why did you push her?" "She pushed me." Sue Sue clearly thought she was in trouble. I told her that I agreed that she should go to time out at school because she broke the rules, but that there would not be any further punishment at home.
I know some people are reading this, shaking their heads. How could I possibly encourage my daughters to fight back? At some point, all children need to learn to stand up for themselves. In my opinion this was a last resort. I don't want my daughters to resolve disputes by fighting, but I don't want them to let other people walk all over them. I know I'm sending them mixed messages. It's OK to be naughty sometimes, just not all of the time. That's a lot for a preschooler to grasp. But in this case, it seemed to work. When I asked Sue Sue what happened to Becky at the end of the time out she said "Becky and I played and she was nicer."