Wow lots of interesting responses, and some assumptions.
This is my Opened Minded read on this, I am far less prudish than most.
#1. The lady with the 12 year old boy was 100% WRONG! If she wished to use the women's bathhouse for her son to shower in she should have first made sure the bathhouse was clear. Once clear then she should have hung a sign on the door that a 12 year old male was inside. That said she is now tying up all the women's showers in that space until they are done.
Can you see a adult male taking is 12 year old daughter into the women's bathhouse!! We already covered the daughter into the mans.
This is a case of the adult not using good judgment!
I have been at more than one sporting event, in the men's restroom using the urinal, only to have a woman or two walk in to us a stall as the line was much shorter!!