My club has an area right where you come into the locker room that is called the family changing area. It is off to the right and sort of open. There are lockers in there. It is in both men and woman's locker rooms. This was added when they remodeled and people had complained loudly about older kids of opposite gender, staring. No boys over 3 years allowed in the woman's locker room.
I remember feeling weird when I let my kids go and shower in the locker room alone at one of the clubs I worked at, when they were like 10 and 7. But, we were going somewhere afterwards, couldn't go home to shower. They had been in there so long, I got concerned, so when the first man came out that I knew, it happened to be their school superintendent. I asked him to go back in and check on them. He said they were busy blowing their hair dry! Boy, were they pissed at me.