The infant and junior schools had an associated senior (secondary) school on the same site. Although the infant school had its own headmistress the junior and senior schools had a common headmaster. I didn’t attend the senior school but I can say with certainty (again documented elsewhere in this Forum) that although the cane ruled there, girls were caned much less often than boys.
So, first question. Are you suggesting that, despite society becoming more prosperous, more liberal, and significantly more litigious, and with class sizes and material conditions in schools improving enormously with far less need to keep the children totally cowed to facilitate their education, we subsequently moved into a period where girls in senior, secondary modern or comprehensive schools were subjected to vastly more corporal punishment than had previously been the case? Why on earth would this happen?