when on 0, the locker room is either empty or she is in the shower
The point of setting the variable to 0 is so she's in the locker room area.
It's random chance if she's actually changing in the locker room or if she's taking a shower, hence leaving and coming back if she's taking a shower and you want to catch her changing in the locker room.
The information I give is to the best of my knowledge.
You have to be flexible and use the information as a guide and try and solve problems on the fly as they occur, the information is not meant as a manual where "if you do this" you'll "get that result".