As all things in our reality have positive and negative polarities, so too does the feminine icon Isis. All souls contain a side that is in the light and that which is dark. This reflects the emotionals aspects of third dimension, love very fear and hate.
Isis is a metaphor for the feminine aspect in all of us. Therefore Isis is portrayed as having dual aspects of Light, the goddess, and Dark which links with magic, illusion, time, and alchemy of consciousness, the Trickster, Merlin, etc.
Coming from Egypt she would be portrayed as a dark skinned woman, though in modern times she is fair.
All feminine archetypes in all mythologies, are linked to one soul, be they goddesses, priestesses, Mary, aliens entities, etc. They are all the same soul essence.
Isis was a magician, possibly the archetype for the high priestess of the tarot. She learned her magic from Thoth, although according to some legends she obtainedher powers from Ra himself by tricking him into revealing his name to her, thus acquiring his full magical knowledge.- Murray Hope Practical Egyptian Magic
The ankh [the looped cross of Egypt] which Isis carries as supreme initiatrix may account for some of the oddly-shaped scepters carried by the Black Virgins who, like Isis, often favor the color green. Their greeness and blackness points to the beginning of the opus whose secret, according to alchemists, is to be found in 'the sex of Isis'., The Cult of the Black Virgin
The Templars, imprisoned and awaiting death in the Castle of Chinon composed a prayer to Our Lady acknowledging Bernard to be the founder of her religion. In addition to the numerous hymns and sermons he addressed to her, he wrote about 280 sermons on the theme of the Song of Songs, the epithalamion of Solomon and the Queen of Sheba, whose versicle 'I am black, but I am beautiful, O ye daughters of Jerusalem' is the recurring refrain of the Black Virgin cult.