She can make three books with different skills.
Book of Memory, the skill of the book is memory retention. If a person writes anything in the book, then whatever was written can't be forgotten by the writer for an extended period of time.
Book of Delete, anything written in the book, the writer will forget what he wrote for an extended period of time.
White facility used it to make its workers forget some secrets about itself. The Psychiatrists use the book to make people forget their trauma to some extent.
Though the memory will resurface over time but slowly and in a long interval.
Book of Record. Is more of a normal book with special effects, unlike the other two amazing skills. The Book of Record can only record whatever you wrote in it forever, but what was written can only be read by the writer.