The second daughter of Gorloïs and Igraine, half-sister of Arthur, she was married to King Nentres of Garloth at about the same time her mother was married to Uther Pendragon and her sister Morgawse (Margawse) to King Lot.
Chapman identifies her with “Vivian called Nimue” and makes her the youngest of Igraine’s “witchy” daughters. This is ingenious and symmetrical, but I found nothing in Malory or the Vulgate to substantiate it, or even to suggest that the other two sisters shared Morgan’s talent for necromancy.
Elaine is a French variation of Helen, the name ultimately derives from Greek mythology (e.g., Helen of Troy), and is borne by a number of people in Arthurian romance.
Garloth | The Legend of King Arthur