As several people have now pointed out, there were ladies only compartments on a lot of coaching stock at least in the south-east until well into the 1960s. As far as I recall they were always in non-corridor stock. It became a big debate as to whether it was safer for a woman to travel in ladies only compartments or to avoid them. The argument was that any man with nefarious intentions would know exactly where to go to find a woman alone. And then, with no corridor, there was no escape. On the other hand, they might protect you from the more casual 'opportunist' attacker - or annoyer.
 
Dr Jill Murdoch
Institute of Railway Studies & Transport History
University of York