Tower to Tower — Michelle L. Levigne

'Na and Ambrose set out to rescue her friend Zella, who lives in a tower and grows her hair to make wigs for dragon-tamers. The magic mirror web is down, and all sorts of legal filings are threatening Zella's peace and solitude. Along the way, they encounter Prince Ruprick and his scheming cousin Rumpton, who increases his kingdom through the new, dark magical art called real estate. Rumpton's target is Zella, her tower, and the curse that controls her hair growth business.