The schools that I attended that used CP used it for everything. There were no lines or detention or ISS or sitting out recess. The felt it was quick easy and over with to just give two or three swats with the paddle for every little infraction of their stupid little rules.
I the first few years the cane was only applicable for boys, however subsequently it was an available punishment for girls. I am reasonably sure that girl reused to touch her toes in preference to being expelled. However, before the cane was available to girls ( the insistence of a new headmistress, the headmaster still being in chaege) you are absolutely correct. Presumably, a girl could have been expelled for not attending a detention. Somewhat unlikely but possible. Personally, had I been the parent or guardian of such a girl I would have insisted on her being offered, no demand in her taking a caning!