In the New Year's Honours for 1966, I think Mary Quant got a gong, for services to fashion, presumably. The mini-skirt was about, but not in our school as DW ashcombe has identified. A few years earlier a major step forward in the girls' fashions allowed them to wear pleated skirts - but only in the 6th form, which wasn't very numerous in those days. 6th form boys were allowed to wear a trilby - cool, eh? Both ideas had died out by the time I was in the 6th form in 1964. I still had to wear a cap.
As one who was particularly aware of being at a co-ed school, I suspect that miniskirts could have been a substantial extra distraction. As it was, even when skirts were definitely knee-length, one occasionally saw stocking-tops - and drew breath sharply!