There tend to be far fewer girls in prison. I think this is because in that culture it's traditional for the girls to be in the home, helping their mothers to run the home. The boys are more likely to be out on the street and in the way of trouble and so get picked up more easily. Where there are girls in prison they are generally separate although it was the plight of 'Rosie', a 6 year old girl in a mass cell, that really got the Olongapo project off the ground.
Click here for some illustrations of what was found when the project managed to get into the jails.
I cannot read all the comments here. But I'll tel you of my travelling experience of the Red Cross.