Alanna was my first introduction to YA-fantasy with strong female lead, and I've never looked back since. That said, Tamora Pierce's subsequent work has seemed derivative to me; like she rehashes the same cast of characters over and over, so I have long looked elsewhere. 
 The Will of the Empress was certainly not derivative; characters and setting were all entirely distinct from Tortall, so that was a relief and I managed to finish the book in fairly good time. But the pacing really seemed off: too slow, too predictable; I got bored with the characters (view spoiler)[(for example had to actually skim over Sandry's second kidnapping, and the tedious casting of Zhegorz as a kind of tragic Cassandra figure) (hide spoiler)]. Perhaps a teenager would find the angst of transition into adulthood interesting; I found it dull. Am dabbling with whether to read the next in the series; thus far its protagonist seems equally petulant, so I may skip it...