I need a book similar to these descriptions...?

I have to draw a picture based on a book, but I also want to draw characters based on two people. I either want a book about a knight/prince and a princess ~or~ a princess/peasant and a male pirate be it romance(preferably) or action, except I don't want them to be against each other. Something that fits one of those. Also, I'd prefer if the characters don't have a set look to them, like on the cover.(I don't care if it describes them in the book, I could always ignore that.) And younger ages are best. I know that may make it harder, but ages from 10-18 are preferred. Thanks bros. C: