Board Thread:Questions and Answers/@comment-4623180-20120919141837/@comment-27044180-20151012162450

im not sure but i think she already knew, because i think but im not sure in the first season there was an episode where the water of camelot was dirty and diseases started to spread and then arthur, merlin and morgana went in some kind of cave and then there was this monster and it attacked arthur and then merlin used his magic to help arthur and then morgana said i know your secret, and yeah. :)