In the Hand of the Goddess by Tamora Pierce

Still disguised as a boy, Alanna becomes a squire to none other than the prince of the realm. Prince Jonathan is not only Alanna's liege lord, he is also her best friend -- and one of the few who knows the secret of her true identity. But when a mysterious sorcerer threatens the prince's life, it will take all of Alanna's skill, strength, and magical power to protect him -- even at the risk of revealing who she really is...

Filled with swords and sorcery, adventure and intrigue, romance and suspense, good and evil, Alanna's second adventure continues the saga of a girl who dares to follow her dreams -- and the magical destiny that awaits her.

Alanna's journey continues...

Even though I didn't exactly fall in love with the first novel of this series, I just couldn't help myself from wanting to find out what would happen with Alanna. Would her secret be revealed? Would she fall in love? Would she finally face her arch nemesis, Roger?

Well, you'll just have to read book 2 to find out, won't you?