Yes, I imagine they are.What, are they worried being in a potential life-or-death situation + teen hormones will get them frisky?
But to be fair, it makes sense to have the kids know exactly where to go when shit goes down. And the bathrooms, which are separated by gender, are definitely familiar to everyone. What we should be wondering I guess is why the teachers didn't just let her use whatever bathroom she already uses everyday. Unless, she isn't allowed to use one and this is just another episode of the school being a dick to her.