“Then he was alone.” With this abrupt opening sentence, Hobbie (Hansel & Gretel) launches readers and her hero—a solitary, homeless kitten whose family has vanished—on an extraordinary trajectory.

Girls who grew up in the 1960s through the 1980s will recognize Holly Hobbie — the sweet little girl who wore a blue bonnet and a long dress with a small apron, who was known to love cats. Then ...