General Book of the Tarot, by A. E. Thierens, [1930], at sacred-texts.com
If the Hebrew letter Gimel means the throat (as a canal for sound) and also "the hand of man half closed in the act of prehension" (P.), then it may indeed well stand for the house of Gemini as for no one else; because Gemini is the macrocosmic 'relation between the two' which is potential vibration, symbolised by 'sound,' and this sign rules the hands of man, with which he grips this relation actually. It rules the 'Word, which was with God in the beginning' and words, speech and correspondence in this world below, as above. It means cognisance, from which science may spring later, but it is not science itself. Nor is it 'action' (M.), though it is the origin of, sometimes the pretext for, activity. But it includes indecision, uncertainty, doubt, change, intercourse, reflection, appearance and everything that the sign Gemini may further communicate.
This Empress is indeed "a daughter of Heaven and Earth" (W.), for she represents the sphere of Mercury, Messenger of the Gods, and so this card always bears the meaning of messages and writing, and of news to be heard, instructions to be received.
Twelve (in older pictures nine) stars are placed around her head and this certainly means that down here on earth the messages come to us from the stars,
a gentle hint at astrology. We regret that in the picture of W., the wings, with which the figure is gifted, and the shield with eagle in her right hand, as shown in older editions of this card have been omitted, for both hold a due indication of the element Air. Gemini is the first house of Air, and sound uses the air as its medium. The use of the sign of Venus is not very clear in the picture given by W. because it is not Venus but Mercury that rules the house of the Empress. One of the older editions shows the Empress holding in her left hand a wand with a heraldic lily, a sort of trefoil on its top, very suggestive of the origin of the colour or suit of Wands, which of course has a close relation with the card of Gemini.
Why this idea of the messenger is drawn as a woman, and given the name of the 'Empress' is very well explained by Mr. W. in these words: "because there is no direct message which has been given to man like that which is borne by woman." Woman rules the world. As a mother she is the 'canal' by which the human being is conducted from another world into this one, and as a female she attracts the man, in order to 'double' herself and to impart a double value to life on earth. This is indicated in the image of the Twins, originally Adam-Eve destined to be united by Knowledge. This is the card of Knowledge.
Also of 'universal fecundity' as W. has it.