preceptress

1. (now rare) A female preceptor, or provider of moral instruction; a teacher.Examples: "‘I daily became more amiable, and might perhaps by this time have nearly attained perfection, had not my Preceptoress been torn from my arms, e'er I had attained by seventeenth year.’"; "Her preceptress had never found it necessary to repeat an admonition of any kind, since her arrival at years to discriminate between the right and the wrong."; "She was my sister, my preceptress and friend; but she died--her end was violent, untimely, and criminal!"