Headmistress is used for females; 'headmaster' is its male equivalent. Mrs. Johnson is the new headmistress, while Mr. Brown was the former headmaster.
Pro Tip 2/3
School Authority
Often implies the person with the highest authority in a school, similar to a CEO in a company. If you have any major concerns, you should speak with the headmistress.
Pro Tip 3/3
Formal Respect
Used as a formal title that shows respect to the female leader of the school. Good morning, Headmistress. We have prepared your schedule.