Board Thread:General Discussion/@comment-97.81.193.97-20130315051304/@comment-76.17.214.172-20130319165140

Cora is referring to her daughter's love. Regina's love would have stopped Cora using magic. But without her heart, Cora could not feel her love of Regina.

Rumple tricked Cora into removing her own heart. He loved Cora, but his driving force - finding Bae - prevented him from stopping her. I think that is why he looked so torn up when she told him what she did. He loved her, knew what would happen to her, but was too much of a coward to stop her and find a different way to craft Regina into the Dark Curse caster.