User blog comment:Miskos3/Fairy Tail Chapters 532 & 533, Review/@comment-7070784-20170422053208/@comment-7418318-20170422162909

"she did it before with the Dear Coby book."

The hell? She did nothing with that book except reading it and realizing that it had an ebedded spell in it that would rearrange the letters. We don't even know if she magically sensed it or if she figured it out through logic and intelligence.

That the book re-arranged itself was not Lucy's doing, but the effect of the spell that the author himself placed on. The spell was triggered by the book coming into contact with the son.