Have you noticed that some depictions of Mary Christ (sorry, I dont know her surname), especially 'Stella Maris' and 'the Coronation' have the Moon at her feet.* Something to do with navigation and safe passage ?
Perhaps she is also 'Saturn' , as in Mater Coeli ? The 'Gateway' , 'Queen of Heaven' , The Black Virgin ** , Nuit ?
* actually, on further examination, this appears only on what looks like more modern renditions - a post RW Tarot accretion ? (Interesting question for the history section ! )
** as in the Icon of Madonna Advocata, Basilica di Santa Maria (sorry, cant post a link to a picture)