IMPOSSIBLE

This is impossible!
Forget about the kid. If you want to go to the restroom, you just go. Why do you request the HR lady's permission? The HR lady of course reject your ridiculous request because she has no responsibility to grant you any permission to go to restroom and you do not need her permission in the first place.
This is simply ridiculous. Try this:
Next time when you need to go to restroom on the street, ask a stranger for permission. See if you can get the permission granted.