Board Thread:General Discussion/@comment-24894881-20140503034318/@comment-4975807-20140624014521

Regina sacrificed the heart of her horse Rocinante during her first attempt to cast the curse. I guess that counts as a death since the horse likely died once the heart was sacrificed.

She killed one of the trolls in "There's No Place Like Home" after turning them into bugs.

Inconclusively, she may or may have not killed Marian.