http://www.dafont.com/romance-fatal-serif.font?text=Daughter+of+Winter+Queen+Summer
-Simple, but has some fun stuff going on too.
http://www.dafont.com/imperator.font?text=Daughter+of+Winter+Queen+Summer
-Doesn't get much simpler than this.
http://www.dafont.com/organic-elements.font?text=Daughter+of+Winter+Queen+Summer
-I really like the "W" with this one. I'm not sure about how thin some of the lines get.
http://www.dafont.com/kawoszeh.font?text=Daughter+of+Winter+Queen+Summer
-Very different. It has a middle east feel to it. I like it, though it doesn't fit the first story.
Thoughts? Your ideas will be big for swaying me one way or another, so let me know what you think.
*Update* Final Four:
http://www.dafont.com/romance-fatal-serif.font?text=DAUGHTER+of+WINTER
-All caps on everything but the articles. Drop caps on the first letter (Thanks to Isaac Steward for the idea!). I really like this one, BUT I'm afraid it looks too much like the font used for the Witch Song series--if you give anyone an opportunity to be confused, they will be.
http://www.dafont.com/imperator.font?text=Daughter+of+Winter+Queen+Summer
-If the cover ends up being too busy, we'll use this one to even things out.
http://www.dafont.com/perigord.font?text=Daughter+of+Winter+Queen+Summer
-If we can use it w/ the lowercase "w" and size it up.
http://www.dafont.com/st-charles.font?text=Daughter+of+Winter+Queen+Summer
My formatter flat out said no on Beyond Wonderland.
I like book or movie title fonts to be very clean and these are very decorative. If I had to pick I would say the first one Perigord.