User blog comment:Merlin919/Is Morgause, Vivienne and Gorlois's daughter/@comment-5139779-20120816022431/@comment-5350801-20120816044910

I understand what LokiIsAwesome is saying. Originally we were told Morgause and Morgana were sister's, but that was also under the assumption they were full sisters, same mother and father. Later we find out that Morgana is the child of Uther and Vivienne. Every one from that point assumed that they were still sister's and they shared a common mother.

What is being said is that maybe Gorlois and some other woman were the parents of Morgause. There is no fact that Vivienne is Morgause's mother except what we are all speculating.