Sarah Trimmer, the daughter of John Kirby, a landscape artist, was born in Ipswich in 1741. Educated at a local private school she moved with her parents to London in 1755.

In 1782 Sarah married James Trimmer. Sarah used mutual instruction, a method developed by Dr. Andrew Bell, to teach her twelve children. In an article published in the Edinburgh Review she advocated the use of Bell's methods to spread the ideas of the Anglican Church. This eventually led to the formation of the National Society for Promoting the Education of the Poor in the Principles of the Established Church.

Trimmer wrote several books on education including: An Essay Introduction to the Knowledge of Nature (1782), the six volume, Sacred History Adapted to the Comprehension of Young Persons (1784) The Economy of Charity (1786) and Comparative View of the New Plan of Education (1805). Trimmer also edited The Family Magazine (1788-89) and the Guardian of Education (1802-06). Sarah Trimmer died in 1810.