The book she is writing is the Mir-12 journal that she uses throught the game. Im assuming she didnt write in it that she is the original author so she doesnt know that she herself wrote it.
(God that sentence sounds confusing)
If you do rent it give it a chance. It seems like people go through a sort of "I hate this game" period for the first 10 hours or so. I love the game and would recommend it.