Are you saying no girl of your era smoked or played truant? Or were those offences not punished with the cane? What offences were punished by caning? I’ve heard of boys being caned for being late; for forgetting their games kit; for not doing homework; even for talking in class. Do you really believe no girl ever did any of those things?
They got the form of education that tended to work best for boys across the board, including when it came to discipline. The approach was generally different for boys and girls because it was understood and acknowledged that boys and girls have different generalised characteristics and so approaches didn’t have to be the same to be give both what they needed.