Board Thread:Show-Related Questions and Answers/@comment-25971187-20170907063815/@comment-25971187-20170907105835

All I remember was that in The Thing you Love Most, Regina has no idea that she was the Savior because she kept asking Henry about the missing pages of the book about the Savior. Emma and Henry ended up burning those pages to hide that she was the Savior.

Then, something might have happened before An Apple Red as Blood that I don't remember, but in that episode, Regina already knows that Emma's the Savior, and she wants her gone (not dead because killing Emma would break the curse) because Emma's weakening the curse and that Regina wants Henry all by herself.