Board Thread:Questions and Answers/@comment-3025831-20140303104749/@comment-10860529-20140303130742

I wrote down an explanation on Thea's page, in the fifth and sixth bullets of her notes/trivia section, that her mother is the daughter of a hunter and Swan Maiden. Although technically that makes her a shapeshifter, the 'lore in those tales includes the fact that they can only transform with the use of a feather robe or cloak, and that without it they can only remain in human form.

...then again, considering that other swan maidens are in the Ugly Duckling line, I'm not sure if that counts. Might be grasping on straws here.