'Fish Girl' by David Weisner

Fish Girl lives in a tank in a boardwalk aquarium. She is the main attraction, though visitors never get more than a glimpse of her.  She has a tail. She can't walk. She can't speak.  But she can make friends with Livia, an ordinary girl, and yearn for a life that includes yoga and pizza. She can grow stronger and braver. With determination, a touch of magic, and the help of a loyal octopus, she can do anything. 
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