What is going on? Are we crazy? What is more natural than for a girl to scream out in shock when a boy comes into the women's rest room where she is using the facility? "Get out of here!!!"
No kidding. Duh.
Oh, wait, what if it is a poor confused male who feels like he's a girl in a male body? Should we be concerned more about his feelings? Or should we be more concerned about the privacy and safety of the female in the stall?
Duh! "Get out of the restroom dude!"