User blog comment:Miskos3/Fairy Tail Chapters 532 & 533, Review/@comment-7070784-20170422053208/@comment-5303512-20170424162129

She deciphered it which is like rewriting it in her mind using the book with its contents enneagrams. That is what I meant

There are instances of people with photographic memory, and she also had her wind glasses which reads anything at high-speed. She was hidden, not fighting, and managed to read the book before getting into battle, plus it's magic, don't think too hard.