There were times when I wanted to ban bathroom breaks all together.
My students had a sign-out sheet so that if something did go awry in the bathroom the Admin. could say which kids were in the bathroom at the time of the incident & were therefore most likely responsible for acts of vandalism etc..
I teach grade 4 - constantly going to the bathroom in that age group is almost exclusively a male problem. Grade 4 girls generally do not pester the teacher to go to the bathroom 2 or 3X a day. I only got ticked off with boys having to go constantly not girls.
The teacher in question sounds to me like a nutbar . . . but I suspect she has had to put up with a lot of kids going to the washroom to goof off. It isn't happy when, as a teacher, you feel as though you are constantly being taken advantage of. Her methods of dealing with it though seem extremely unorthodox & punitive to say the least.
What I suspect has happened is that a lot of kids have abused the privilege of going to the bathroom to goof off on her watch. I don't doubt that a lot of pre-teen or teenage girls go to the bathroom to chat with friends, pass notes, or daydream . . . or whatever they do there. I am guessing that when she confronted one of the girls about her constant disruptive behaviour (getting up and leaving the classroom to go to the washroom to chat with her friends) the girl replied that she had to go because she had her period & it was an emergency. The teacher is getting back at them. Bit of a power struggle is possibly the case as well.