The Christening Quest by Elizabeth Ann Scarborough
Going on a quest with a handsome prince might sound like a dream, but Prince Rupert's cousin Carole comes to feel that it isn't all it is cracked up to be. Carole agrees to accompany her hunky cousin to Miragenia to christen his baby niece. But it's really hard to even explain the situation to anyone: how the little Princess was stolen from her mother's side by Miragenians who demand fifteen years of the first-born's life in exchange for a bit of help during wartime. Or how the baby was taken before magical christening gifts could be bestowed upon her for her protection and character development. The ladies surrounding Rupert (also known as Rowan the Romantic and Rowan the Rake) don't care about some baby and don't hear anything about the mission because they're too busy sighing over him. Crowd control is an obvious problem, as is extricating Rupert from more than one involuntary engagement. When at last the two, with the help of dubious questing companions including a love-stricken pink and purple dragon, arrive at the theocracy of Gorequartz where the baby has been fostered out to a queen, they find themselves in trouble of a completely different complexion. Their most deadly nemesis is none other than a giant crystal "god" seemingly created in Rupert's own image!