Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Determined
Even though things are confusing and Tiffany finds herself in a not-so-good situation in The Wee Free Men, the tone of the story isn't one of weeping and bemoaning the state of affairs. Instead, like its protagonist, the story plows onward. There are things to be done and an evil Queen to be defeated, after all, plus a sticky little brother to bring home.