Mary Shirtliffe teaches Basic Magical Defense and Practical Magical Exercise at Charmbridge Academy, and administers that part of the Standardized Practical Assessment of Wizarding kNowledge. She is also in charge of the Charmbridge Dueling Club.

She is also a reserve Witch-Colonel in the Regimental Officer Corps, and thus is in charge of Charmbridge's JROC company.

In September 2010, she and Groundskeeper Fletcher belatedly came to Quick's aid after a murder of crows attacked the ninth-grader on the Invisible Bridge.


Shirtliffe wasn't as old as she'd first appeared, but her short, severe haircut and serious expression made her seem older. Her black leather jacket, jeans, and leather boots were incongruous at Charmbridge; she looked less like a witch than a biker. Alexandra noticed the teacher wore a pair of earrings set with blood-red stones.