Thanks for your reply @theinkwell, he did nothing to deserve it but still, she gave it because she deserves the peace of mind.
Looking at the story, the readers are meant to understand that she is emotionally exhausted. A person who believes in fairy tales is usually happy with their fantasies, having the fantasy ruined has damaged her, to repair herself she forgave him.
That is why I wrote at the end that for the very first time in four years, she dreamt(meaning she had had trouble sleeping and dreaming) how hard it must have been for a fairy tale lover!