What are the comparisons between Harriet and her two friends?

Harriet M. Welsh

An eleven-year-old girl who is an aspiring writer and avid spy. She follows a "spy route" every day after school and takes detailed notes in a notebook. Harriet is a precocious child and a keen observer. She loves routine and follows her own set of habits and patterns of behavior. When her nanny leaves and her notebook is discovered, Harriet is forced to deal with major challenges to her formerly organized life.

Ole Golly

Harriet's eccentric, whimsical nanny. She encourages Harriet's desires to become a writer and is in many ways much closer to Harriet than is Harriet's own mother. While she appears rough and strict, she genuinely loves and cares for Harriet and is invaluable in Harriet's life. She leaves her job after she becomes engaged, as she deems Harriet old enough to live without her care; however, she continues to be an invaluable presence in Harriet's life and comes to her aid when she is in her most vulnerable state.

Sport

One of Harriet's best friends, a boy that loves to play soccer. He lives with his father, a writer who is largely unsuccessful for the duration of the novel. As a result, Sport takes on many of the domestic responsibilities around the house such as the cooking and the cleaning. Sport and Harriet's friendship becomes strained once he sees that Harriet has compared him to an "old woman."