Let me give you an idea. You can write down your name and telephone number in your book. Sit with her next time you read in the library. After ten minutes, ask her politely that you need to go to the bathroom and ask her to check your position. If she agrees, it's over. You can leave without going back to the library.

There will be two outcomes. First, the girl will contact you and return the book to you. By the way, you will thank her for inviting you to dinner or something, and you will get familiar with it in the long run. Second, your book "goodbye" to you, which also proves that the girl is not of good quality and is not worth cherishing. (Note: Use your useless books as props, otherwise you may be "lost", I hope not. )

I wish you success!