For an interesting, semi-cozy light mystery, read The Sweetness at the Bottom of the Pie, by C. Alan Bradley. The narrator is a ten-year old English girl but don't let this put you off. It's a fairly complex mystery, with good pacing. Heard the author is going to write more in this series, hope that's right.

Other adult British books with non-adult narrators; Black Swan Green by David Mitchell; The Dead Fathers Club by Matt Haig; When We Were Romans by Matthew Kneale; and of course the immortal Adrian Mole series by Sue Townsend, beginning with The Diary of Adrian Mole Age 13 1/2. The speakers vary in age but all of these books are well worth your time.