Board Thread:Spoilers!/@comment-413929-20150114222625/@comment-24674051-20150327140549

One difference between Emma and Regina. Regina had zero experience with Magic when Cora killed Daniel, and was very slow to embrace the "evil" side. You see this in the various training sessions through the episodes. She had the temperment immediatly, just no real way to express it, and because of her relationship with Cora, she did not want to become what she considered to be a monster.

Emma, on the Other hand, has a fairly good grasp of magic, and has embraced it. She has shoved hearts back into people (at least Hook), so is only half a step away from ripping them out. She has an emotional side that is easy to trigger. And, honestly, Emma grew up in our world with little to no privelege. She has plenty of kindling on the fire (so to speak) and I think it would be totally in character for her to just simply erupt given just the right spark.

And given her trust issues (or maybe it would be better to call them lack of trust issues) to begin with, finding out that her parent's (primarily her Mom) lied to her may be just the catalyst needed.