From "Merlin: The Kindness of Strangers (#5.10)"
She's drawing you in, Merlin. It's a trap. She knew your real name. There's only one explanation for that. Alator told Morgana who you really are and she has sent this woman to lure you to her.
But I looked into her eyes. She meant no harm.
You think a sorceress of her power couldn't feign any look she wished?