dictatrix

A female dictator.

Our principal domestic, in dignity and station, was Mrs Primmins, who was waiting gentlewoman, housekeeper, and tyrannical dictatrix of the whole establishment.

Prudent mammas were generally of opinion that the height of felicity for a daughter would be the position that should enable her to be the mistress and dictatrix of his ample fortune.

A dictatorial entity personified as female; that which dictates.

the Church of Rome which is the great dictatrix of dogmaticall resolutions, and the declarer of Heresy

1756, George Anderson, A Remonstrance against Lord Bolingbroke’s Philosophical Religion cited in a review in The Monthly Review, Volume 16, 1757, p. 240, […] how can you […] plead a religious conscience as a dictatrix of what is morally good and evil, when you deny God’s moral attributes?