Can I also call that when Emma is surrounded by people from the town, Regina is tied to a tree, and Emma holds out Charming's sword saying”you took away our happiness, we're going to take away yours”, in a preview for the season finale, that the whole scene is just Regina's nightmare, because she's starting to get really nervous!
Done.
But I believe that it is through this dream or vision that Regina figures out who Emma is and that she must get rid of her. So I am calling that.