User blog comment:Knightofthecart/Morgana has turned her back/@comment-118.100.86.41-20120312042814

I think Morgana didn't know that she was the source of the enchantement. She was pretty confused in that episode, and Gaius did not know the whole story. But in my opinion, I think the point when Merlin poisoned her would have been a big factor into why she turned against her friends, or at least Merlin.