Sunset Shimmer's element??? · 1:41am Oct 3rd, 2016
Based on Legend of the Everfree, perhaps it's empathy! After all, when she touched or brushed against someone, she saw into their heads.
Also, guess who's watching Legend of the Everfree for the first time
IIRC, one of the writers said it is Empathy but that isn't officially confirmed.
I think that, because the Human World didn't have magic until the Sirens were exiled there, there was never originally 'meant' to be an Element of Magic for that world. So, technically, the Element of Magic is the Seventh Element. Sunset's element is the thing that is left when you remove Magic from the equation - Friendship. It was Friendship that made her see beyond the Sirens' psionic manipulations. It was Friendship that made Twilight reach out to Sci-Twi rather than try to destroy her. It was Friendship that drives her ability to understand how others think and behave; to prioritise Sci-Twi's feelings over confronting and denouncing Timber despite the pile of circumstantial evidence against him.
So, yeah: Sunset Shimmer is the Bearer of the Element of Friendship.