Squire by Tamora Pierce

In Book 3 of Tamora Pierce's Protector of the Small sequence, 14-year-old Keladry of Mindelan is ready to begin training as a squire after undergoing four grueling years as the first girl to be officially educated as a page. Disappointed at first that Lady Alanna (whom we first met in the Song of the Lioness Quartet series) does not choose her, Kel is delighted when gruff, good-natured, down-to-earth Lord Raoul takes her on. The next four years prove to be tough but happy, for the most part, as Raoul and most of the others in the King's Own (a corps men --plus Kel-- that enforces the law and helps local nobles deal with problems such as centaur attacks and forest robberies) treat Kel as an equal. Throughout, Kel is physically and mentally preparing herself for the final test in the Chamber of the Ordeal, in which fourth-year squires must successfully face their greatest fears before becoming knights.