I have met Erishkigal, and she is fair skinned, has long blonde hair and basically looks very Aryan, that image on astral art of the Gods of her is very wrong.
Nergal being one of Satan's son's, he too is fair skinned (Haven't met him, but since he is Satan's son, the son of the most Aryan being in the universe, he'd obviously be fair skinned).
I don't want to write too much about her, because there is a reason she's not listed on the JoS. Some Gods prefer their privacy and don't want to be known publicly, so to respect her privacy I don't want to say much about her, but I will say, if you have the chance to meet her and work with her energy it is very wonderful.
She is a most wonderful Goddess. She gives me a somewhat simmilar impression as Mother Lilith, those we can benifit from working with her will learn this when the time comes and she will come to to you herself.
Also I don't know how she feels about being summoned, so keep that in mind in case you'd want to work with her and remember that not all Gods want to be publicly known yet and be consulted by a large number of people.