How do we know she's not a real nurse?
1. The coat is spotless.
2. Very few nurses wear these white coats anymore.
3. Only people in training carry books in their pockets. A real nurse's pockets have tape, scissors, hemostats, pens, a granola bar, a "buy 500 get 1 free" Starbucks punchcard, and a hospital ID.
Another point: Although I don't know what Nurse K looks like, this could be a picture of her, taken at the critical moment when she's tired of putting up with a drunk patient's shit and is smilingly drawing her Taser.