My DC is 8 and until now I've been selecting books for her to read based on her interests. The only time she requests a book is if it is in the series of a book she enjoys or is by a familiar author. I'd like to transition the role of book selection onto her, but I'm not sure how to go about it.

https://imaginationsoup.net I have this bookmarked. She puts up pictures of the book covers.
www.goodreads.com
I still recommend books to my 10yo ds, but he also got recommendations from friends and librarians. harder to manage in this remote era :( He enjoyed reading the Space Case and Bad Unicorn series, and speculative nonfic like what if. we’re transitioning him to magazines like wired and make so he’s not always hunting for books...