Kate is a human girl who lives with her parents and their tenant, Mrs. May. She is described as wild and willful, attributes designed to mirror those of the primary Borrower character, Arrietty. It is clear that Mrs. May understands and appreciates Kate’s adventuresome nature, for she uses this exciting story to entertain the girl while simultaneously attempting to teach her the more mundane and traditional skills of crocheting, quilting, and other ladylike tasks. Thus, she deliberately appeals to Kate’s natural wild curiosity by telling her the story of the Borrowers.

Kate’s character is never fully developed in this particular novel, and she remains fairly static throughout the novel, for the main purpose of her presence is also to represent that of the reader, who like Kate, sits and “listens” to the tale that Mrs. May weaves. However, as The Borrowers book series progresses further, Kate comes to represent a fictionalized version of Norton herself, as she goes on to write down the Borrowers’ stories to entertain her own fictional children.

In The Borrowers, Mrs. May is an old woman and the sister of the primary human character, a child known only as “the boy." She is very proper and sensible, but her story reveals that she has preserved a childlike sense of wonder in her believe in the existence of tiny people called the Borrowers, and this sense of wonder makes itself even more evident in her eagerness to share and embellish this amazing tale for Kate’s amusement.