Here's why:
* Target Audience: The book is written for children, focusing on themes and characters that resonate with young readers.
* Magical Elements: The story features magical creatures, underwater adventures, and a main character with a unique ability (being able to breathe underwater).
* Lighthearted Tone: While there may be some suspense, the overall tone of the book is whimsical and lighthearted.
It's also possible to categorize the book as fantasy adventure, as Emily embarks on a quest to solve a mystery and face challenges along the way.