For a housewarming gift for my wife, I made a woodworking project by building shelves for her books. She still says it’s the best gift she’s ever received.
Good gifts for book lovers are solid bookends or nice sets to keep large art books from falling over.
Books are always a hit! My friend gifted me a three-month subscription to the Book of the Month club, letting me pick titles or be surprised. Books never disappoint!
Would a premium membership to StoryGraph for tracking reading be appealing to her?
Some local bookstores offer personalized curation services. You tell them your interests, and they select books for you. More options might be found online.
How about getting copies of her favorite books signed by the author?
A book nook decorative piece could be a nice addition.
Book nooks are cool, although they can be pricey. A Folio edition of her favorite book is also an excellent choice.
A first edition or signed copy of one of her favorite books would certainly be a hit.
It seems like you have all the book-related gifts covered. Maybe consider adding a non-book gift to show you know more about her.
If she reads oversized books, fun bookends would be perfect. They come in various creative shapes.
Depending on what she enjoys, a book subscription could be a great gift. Fairyloot, Owlcrate, and Illumicrate are popular choices for special editions.
Choose some books you think she’ll love. Read one and lightly annotate your thoughts before gifting it. It makes reading together more special.
If she has an e-reader, consider a clickable digital page turner. I have a ring version that I really like.
My boyfriend surprised me with physical copies of a series I love, and even included a signed copy of the last book. It was the most thoughtful gift ever! 
Consider a book pillow, a reading light for dark places, or a ‘from the library of ______’ stamp. My fiancé took me to various shops for my birthday, and I ended up with so many new books!
A Book Beau reading pillow is amazing for comfort while reading. They offer book cases too if she likes to travel.
Check out Etsy, there’s tons of book-themed stuff available.
Take her to her favorite bookstore and give her $100 to spend.
You could also check Out of Print for cool merch for book lovers, including apparel and accessories.
Try looking for a book nook, it’s something that you can build and some even light up—super fun for a book lover!