So in regards to the quote Sarah signed on the giant ACOTAR book, here is some context for that quote;
A line that signifies a shift in personality, in particular the shedding of Feyre’s human persona in favor of her new stronger abilities as Fae.
Interestingly we also get a quote about Nesta that similarly relates her to a wolf:
Nesta never belonged among the humans, always too wild and destined for something greater.
It appears that the author is very fond of associating the Archeron sisters with wolf imagery. And then of course we have this:
Elain “growing claws” as she begins to shift away from her more passive personality traits. Almost like a wolf in sheep’s clothes.
Brave when she has to be, like a cornered wolf. Signifying the flouting of her human traits and persona, much like what Feyre experienced.
SJM associated both Nesta and Feyre with wolves, and there is no way she will not do the same with Elain. Elain is not what she seems, stifled and hidden by the boundaries of circumstance and society. But when she is called upon, the claws come out. Kicking off the cauldron, slamming her feet into Hybern hounds, stabbing the King of Hybern. She was never a sheep, people just were too consumed by the teeth and claws of her sisters to notice Elain had those same defenses too.