the set out a bit confusing. Couldn't properly put the characters in their proper place. Maybe subsequent chapters may unrevealed and sort out the mystery for my understanding.
The book thing makes no sense tbh.
She just got memories from/transmigrated to a different life. But why does she know/think its a book and not just another life?
It doesn't sound like she read the book, she just randomly realized when she got the memories from her new body.