The Deadpan Snarker comes in many forms; it could be the non-action guy, the sidekick, the Weasel Mascot, and even the cat. This trope deals with snark coming from a little girl.
The humor here is that we don't usually think of an adorable little kid as being sarcastic, and this character type is both smart and perceptive, capable of pointing out exactly what other characters keep concealed - [...] [tvtropes.org]