The Empress has changed less between the fifteenth century and the present than almost any other trump, which makes her useful as a control. A seated crowned woman with a shield or an eagle appears in the earliest hand-painted Milanese decks, in the French woodblock pattern, and in the twentieth-century occult decks, and the through-line is unbroken. Where other trumps were renamed, renumbered, moralised or quietly dropped, she was simply reprinted.
That stability is itself worth noticing, because it undercuts a common assumption. If the tarot were an encoded doctrine, one would expect the doctrinal cards to be the stable ones and the decorative cards to drift. What actually happened is the reverse. The cards that moved most, the female pope, the pope, the Devil, the Tower, moved because they were socially awkward, not because they were doctrinally important. The Empress stayed put because a crowned woman with a shield offended nobody.
Her fifteenth-century sense is straightforwardly civic. She is temporal authority in its female form, paired with the Emperor as the Popess is paired with the Pope: two secular powers and two ecclesiastical ones, at the bottom of the trump order, above the tricksters and below the virtues. The reading of her as Nature, fertility, Demeter and the generative principle is a later overlay, arriving with the occultists in the nineteenth century and reinforced by the wheat and the pomegranates in the 1909 drawing. It is a good reading. It is not the one a Milanese card-player would have recognised.