Court de Gebelin in his
Game of Tarots (1781) mentions a picture of an ancient monument in Boissard's
Antiquities known as the
Simulacrum Fidei [A Picture of Fidelity]. The monument shows a man and woman with a child between them. Next to the woman is the word Veritas [Truth]; next to the man is Honor; and above the child's head is Amor. It is said to symbolize marital union, the man and woman held together in a bond of love, represented by the child. Waite also mentions it in his commentary on the Lovers in Part 1 of the
Pictorial Key, but he doesn't seem to be very familiar with it.
Here's a link to a picture of the actual monument from the first century. Supposedly the inscriptions were added at a later date.
http://www.rdklabor.de/wiki/Datei:08-0831-1.jpg
Here's a link to a later illustration based on it (1621).
http://www.emblems.arts.gla.ac.uk/alciato/picturae.php?id=A21a009
Check out the Lovers from the
Vieville Tarot. It looks like a man and woman with a young man between them.
The question of where the older woman and younger woman comes from originally is pretty murky but I don't think it's too much of a stretch to say it could have begun with the
Simulacrum Fidei. The man in the 1621 illustration above has a somewhat feminine appearance. The man could have simply been transformed into an older woman; add Cupid and
voilĂ , you have a picture of a young man leaving his mother and beginning a new life with his young bride.