Pretty much everyone of reading age, from grandparents to 11-year-olds, are reading Shannon Messenger's Keeper of the Lost Cities series.
I think a 13-year-old niece discovered these books and suggested them to my sister. My sister knew I needed a book to co-read with my kid this summer because if I do not discuss books with her chapter-by-chapter she forgets everything she just read. When I told my mother about it she already had it on hold at the library. I am certain my 15-year-old niece read the entire series in about 1 day (eight books) just so she may tell us all the problems with the plot, characters and covers.
IT IS JUST HARRY POTTER WITH ELVES, UNCLE JASON!
Another branch of the family is likely to start on this once my awesome 8-year-old nephew finishes reading the most recent Star Wars: Thrawn books.
Shannon Messenger's universe is absorbing. My daughter and I were immediately drawn into this reality where elves, goblins, and all sorts of fantasy creature are real. Evidently, ages ago, humans acted like real turds and all the magical folks decided to retreat to their own 'impossible' to find cities. Either waiting for a day when humans could be trusted or just sitting around waiting because humans never will be trustworthy, elves seem to spend all their time convincing themselves their dystopian society is a utopia. Unwilling to engage outside their slowly rotting culture, packed with class issues and bitterness, the elves fail to notice BIG TROUBLE is brewing with the humans. Until an impossible young girl shows up and turns their world on its head.
Sophie was raised by humans, but is most assuredly an elf. In a gut-wrenching turn of event young Sophie is forced to abandon her family, and as one of the bravest young characters thrust into a magical world that I've ever read about, makes some very hard and very mature decisions. Even when Sophie can't control her emotions, because she is a teenager, she is an excellent example of applying rational thought to her problems, or asking trsuted adults for help. Her friends, Biana, Fitz, Keefe, and Dex are all real-ish kid characters as well, and they way they interact and solve their problems struck me as excellent for a kid to be reading... and some adults.
I've read the first book in the series, which is available via Kindle Unlimited. Libby had a huge wait on the first few books in this series (6+ weeks) and so I am waiting for the second. I am pretty sure I'll finish the series this summer.
My daughter was assigned a Wrinkle in Time for school, so she's paused until that classic is finished.