Dear Aunt Debbie,
I love your suggestions, and will be sure to check them out. Our nightly vacation reading of Nancy Drew is getting Eleanor so excited that she literally cannot sit still -- she's up and down, sitting on the floor and on the arm of the chair, moving closer to and farther away from the book with the intensity of the suspense. I look forward to more mysteries with her.
I'm realizing, thinking back on it, that a few of our favorites have also been mysteries of a comic sort, so disguised that I don't think of them as mysteries first. I wrote a while back about the fabulous Ottoline and the Yellow Cat, by Chris Riddell; in the year and a half since we first read it, we have acquired the other two Ottoline books: Ottoline Goes to School, and Ottoline at Sea (sadly out of print). All three books are graphic novels, extremely quirky, mysteries of a sort but mostly just tremendously, enjoyably odd. In Ottoline Goes to School, Ottoline and her friend/caretaker/tiny hairy Norwegian bog-person, Mr. Munroe, enroll along with Ottoline's new friend Cecily in the Alice B. Smith School for the Differently Gifted. There are very few pupils, each astoundingly rich and odd, and each with a unique pet (the son of the Invisible Man, for example, has an Invisible Dog). Ottoline tries to determine what her Different Gift is; meanwhile, the school appears to be haunted by the ghost of the Horse of the Hammersteins, who Cecily has a lot of stories about. While that ghost is revealed by the end not to be real, there are some friendly true ghosts who wander through the pages, and can be great fun to pick out as you go along. The story is about neediness and friendship -- Ottoline has to navigate her new exciting friendship with Cecily, who tries to pull her away from Mr. Munroe; ultimately, Cecily's loneliness for her parents turns out to be a major cause of her unhappiness. (A funny moral, given that Ottoline never seems to see her parents, the Roving Collectors, but oh well.) Ottoline at Sea contains a trip to Norway, a bog monster, and a pair of "bog-goggles" you can use to see hidden pictures in the book. Eleanor will pore over these books for long periods of time.
For the early reader set, there's the Cynthia Rylant series The High-Rise Private Eyes, more humor than mystery, as I've written about before, but pretty great.
And speaking of great, let's not leave out Nate the Great, those odd little meandering books by Marjorie Weinman Sharmat. Nate's mysteries always involve him eating a lot of pancakes, and at least in the several we've read, usually also involve slightly odd female friends and a number of cats. The stakes are low -- a drawing disappears, and Nate figures out that his friend's little brother drew over it -- and the tone is thoughtful.
None of these make Eleanor squirm in her seat, but they do keep her interested.