In the following essay, Devereaux examines the author's emphasis on heroic female leads as role models for young female readers.

If you have not heard of Tamora Pierce, chances are that you do not have a preadolescent girl in your life. Enormously popular, Pierce is a best-selling and prolific author of girls' fantasy novels, loved for her strong female heroines and quasi-medieval magical realms. Her characters are not literary cousins to Harry Potter (whom they precede, having first appeared in 1983) but a more particular type, featured also in the works of Robin McKinley and others: the girl warrior. They know their way around dragons and shape-shifters, jousts and to-the-death battles, and they are relative strangers to anxieties about their looks, status and power.

To date, Pierce's novels have come in "quartets," or series of four; three linked quartets have followed three girl warriors in the land of...