The title Beauty Queens is no mystery. There's no poetic metaphor that hints at the deeper meaning within the book. Beauty Queens is the type of title that simply tells you the subject of the story.
That's right. It's about beauty queens.
However. Notice it says "queens," not "queen." Before you even open the book, the title tells you that this story has no main character. It's about a whole group of girls who start out all gunning for the same thing, but in the end come to figure themselves out, as individuals and as former pageant contestants.
Emphasis on the former. This story's not about the crown. By the end, the title is almost ironic: sure, they're still beautiful and all, but they've gone way past the original beauty queen stereotype. How's that for sneaking a poetic metaphor in there after all?