Sarah Agnes Angus Brewster

Sarah Agnes Angus Brewster or Agnes Angus Brewster (29 April 1874 – 29 December 1957) was an Australian headmistress and naturalist. She was the founding head of Sydney's Hornsby Girls' High School.

Life Brewster was born in Sydney in 1874. Her English-born mother, Sarah (born Morton) gave birth to her in Belmore Barracks. Her Scottish-born father William Brewster was an armourer and they already had nine children when she was born. and she became a demonstrator of science at Sydney Technical College. In 1921 Brewster was one of the first two women who they made a fellow at Sydney Technical College.

In 1916 she and Constance M. Le Plastrier published Botany for Australian students. Brewster was the illustrator of the book. The book was said to be "the best work to date on Australian botany".

She became the founding head of Hornsby Girls' High School in (one source says) 1931 During her seven years at the school she established plants into a designed garden, she put books in the library and pictures in the corridors. Courts were built so that the girls could play basketball and tennis. She retired on 31 January 1938 and she took a renewed interest in science. In May 1965 the Head Deaconess of Hornsby School dedicated the Agnes Brewster Memorial Library to her.