What Age To Stop Using Diapers What Is An Appropriate Upper Age Limit For Children In Opposite Sex Locker Rooms?

What is an appropriate upper age limit for children in opposite sex locker rooms? - what age to stop using diapers

I my college gym and locker rooms (including semi-private showers). However, the rent applicable to the swimming pool (and thus the use of dressing rooms) to a private swim club in the region, tutoring for children in the afternoon. Many children are accompanied by minders. There is also a mix of different cultures. Some women, nurses and parents to bring all children in the women's locker room - including children who are 5 or 6 years. The only policy they have is that children are not in the gym and locker rooms are allowed ... which obviously contradicts the rental pool for swimming lessons for children. The staff was the problem with parents or nannies, but with little effect, as I sing a proper follow-up dressing rooms.
So, what is the appropriate age for children to prevent the locker room for women? I am very well with those of the layers, but what is the cutoff age? What is the acceptable level?