as an old booking clerk, certainly in NSW, in all carriages with compartments, be they first or second class, there was a compartment reserved for ladies, the restriction was that it was restricted to ladies and children.
As i recall, the long distance country trains that consisted of air-conditioned stock had a section at the rear of the carriage for "Ladies"'
When the feminist revolution started, this was lost, which was a bit of a shock, formerly the call had been to address the discrimination, funnily enough, in a time long past (the early to mid 1970's ) in Sydney, the large city stations employed a Ladies Waiting Room Attendant to do what was necessary, there was even an enameled hat badge showing "LWRA"' part of their job was selling "Genetex"napkins for the use of the fairer sex.
On Afternoon shift they would bring their money in and pay it into the Booking Office, remember this was at a time when there were 2c slot locks on the toilets.
Well I remember counting buckets of filthy 2c pieces and rolling them into bolts for the bank.