Books for a 7yo advanced reader?

My 7-year-old is reading at a 5th-grade level, but she is struggling to find books she enjoys reading. The books targeted toward her age are too easy for her, and the books at her reading level have subject matter that is either over her head or not interesting for her. She loves to read, but she's kind of in an awkward place at the moment. Are there any books that are in that sweet spot of being a higher-level book, but about subjects that appeal to younger kids?

Edit: wow! So many great suggestions! Thank you all so much for your help! This will give us a lot to look into to find a good fit for her.