Mrs. Piggle-Wiggle is the eponymous and primary character in the novel. She is a complex but ultimately enigmatic character. Her motivations for the friendships with children are never explained in detail, and it is unclear whether she is telling the truth about elements of her past (like that her husband was a pirate). While the novel is in third-person omniscient point-of-view, it omits descriptions of Mrs. Piggle-Wiggle’s thought processes. The interior thoughts and emotions of children and their parents appear throughout the chapters, but Mrs. Piggle-Wiggle’s are excluded. She is characterized in the first chapter via a description of her actions and relationships with the children, then in later chapters by her conversations with the parents and the cures she suggests. Her character remains constant throughout the novel, and she does not have a character arc.

Physically, she is “very small and has a hump on her back” (9), as well as “brown sparkly eyes and brown hair which she keeps very long, almost to her knees, so the children can comb it” (10). Her skin is “a goldy brown and she has a warm, spicy, sugar-cooky smell that is very comforting to children who are sad about something” (10).