That's why it's bad writing. Instead of wishing for an actually "legendary" spell, Fern picks one that fits the author's writing quirks. Quirkiness trumps quality. I don't like it. I just finished watching a rom-com with Vince Vaughn and Jennifer Aniston that ends with them still broken up, but both happy. I understand the message the writers of the movie want to tell, but I still dislike it, because I wanted them to get back together.