Board Thread:General Discussion/@comment-25926288-20161128015930/@comment-25375217-20161130060752

Not only did Blue say that her magic can't save the baby, but she specifically stated that it was because Belle didn't have magic that she would be able to.

Maybe it has something to do with a specific trait of the Black Fairy that we'll learn about later. We know she somehow got her hands on a wand that could recreate any spell; maybe she has the ability to absorb magic to power herself up or something. I dunno.