Agnes, Hamnet’s mother, is at the center of O’Farrell’s narrative, appearing in every chapter except for the 11th one, which explains the plague’s trajectory. While Shakespeare’s wife was conventionally known as Anne Hathaway, O’Farrell used the name Agnes, which was written in Hathaway’s father’s will. O’Farrell decided to make Joan Hathaway Agnes’ stepmother so that she could give her a more unusual maternal influence in Rowan, a fairy-like woman who grew up in the forest. The otherworldly quality that Agnes has inherited from her mother is evident, as she goes around with a kestrel, a fierce and stealthy bird of prey on her shoulder. She gives this bird up on her marriage to the Latin tutor, as she exchanges a rural existence for a more urban one.

She is tall and pale with an “unsettling, wrong sort of beauty” (174). Her dark hair is “ill-matched with the golden-green eyes” and her teeth are “evenly spaced but pointed, like a fox’s” (174). In combining feral attributes with the contemporary beauty tropes of fair skin and bright eyes, Agnes’s looks are a fitting counterpart to her dual nature; she is a dutiful wife and mother but is also a healer with a “witch garden” of medicinal plants and bees that she attends to without a veil (15).