Sentence:  And even as her pure young voice arose above the screams of the departure whistle, she threw a double back-somersault on the quarterdeck, cleverly alighting on the spikes of the wheel before the delighted captain. / "Jingle my electric bells," be said, looking at the <WSD>bright young thing</WSD>, "but you're a regular minx—" 
Meaning of the word marked with <WSD> tags:  One who is youthful, clever, eager, and high-spirited in manner and attractive in appearance.