|Nickname||Roz/ Ms. Mullins|
|Occupation||Principal of Horace Greene Prep|
Rosalie Mullin is a very uptight principal. She is intelligent, serious, uptight, and responsible. She does care about the students well education and does take her job seriously but does to seem to have a love for rock n roll deep down.
It is revealed that she was "not always wound this tight", but the pressure of the parents wanting everything to be perfect has made her into someone she never wanted to be.
She is always strictly dressed. At one point she is seen wearing a blouse and necktie with a tightly buttoned blazer. She also is often seen wearing a turtleneck sweater, sometimes under a blazer.