Board Thread:General Discussion/@comment-26443838-20150728003910/@comment-26237024-20150728195201

["Hook did a terrible thing to Ursula, and yet Emma forgave him easily, why couldn't she have done the same with her family?!"]

Because Emma has spent all of her time in Storybrooke regarding her parents as "white-hat" heroes. In fact, she regarded them in this matter so much that she was willing to brush aside Snow's murder of Cora. She used Cora's moral compass as an excuse. But the kidnapping of a child wasn't something she could brush aside, especially since Snow and David went out of their way to keep their action a secret from her.