Dragon in Distress — Mercedes Lackey

No matter how many princes woo you, you need some standards: "If I were ever to marry, which I don't plan on," Princess Rowena said firmly, "I'm sure I would want a husband who had some sense of self-preservation. Camping out on a ledge just outside a dragon's lair does not betoken any great degree of intelligence."
Unfortunately the prince did manage to kidnap her, and the dragon needed help from Tarma and Kethry to get her back.