Catherine, referred to throughout by her nickname Birdy, is the dominant voice throughout the book. The protagonist is writing a diary of the events of her life during her 14th year—1290 to be exact—in the village of Stonebridge in England. Because she is so young and relatively naïve, her narration can be considered unreliable, filtered through the biased lens of her stubbornness and inexperience.

She resists her training to become a lady, preferring instead to seek the company of the goatherd, Perkin, and wishing for adventurous travels rather than domestic chores. She harbors crushes on her Uncle George, because of his handsomeness and his tales of the crusades, and on Geoffrey, a young knight in training who she finds physically attractive but intellectually incompatible. Like many young teenagers, Birdy’s emotional state and desires fluctuate. On one hand, she can reveal herself to be self-centered and childish, as when she curses Uncle George and Aelis for their attraction to each other. On the other hand, she can be incredibly thoughtful and generous, as when she paints granny’s portrait for Perkin or stays by her mother’s side after the birth of her younger sister.

Birdy is also troubled at injustice, in what she perceives as unfairness toward herself and in the inequality she witnesses between classes.