The Archimage's Fourth Daughter - Lyndon Hardy

Alodar placed his hands on Briana's shoulders, paused for a moment more, and then said softly, "The answer is no."
"You can't do that!" Briana yelled back. "Even the Archimage has limits to his power. You admitted as much yourself. You cannot order me around like some serf of an Arcadian lord."
"I do not order you to stay because I am the Archimage," Alodar said. "I do so because I am your father."
Briana felt the anger well within her like a brush fire suddenly out of control. She clinched her teeth so as not to say more. The library page had a key to this council chamber, she thought fiercely. It might take more than a single kiss to get it, but that is what she would have to do.
Fourth book in the Magic by the Numbers series. A stand alone novel that does not require any of the preceding volumes need to read first.