hey ya'll!

I am on a desprate hunt to find a really good book I want to finish, but I am having no luck finding it so far. This is not fanfiction, or anything on AFF; this is a book that was published and I read a year or two back, but I really wanna find it again XD

What I remember is the title I thought was "Desertlands" or something close to it. The cover is of a girl's shadow, her back to the reader and the red desert around her. 

What i can remember of the story is there was the main character girl, whom I'm pretty sure had a twin, and they were born under a special moon. But because they were twins, and or possibly something with the moon, one random day some hunter-bad guys showed up, and kidnapped the girl's brother. She then set off on her journy through the desert (because that's where she lives in this dystopain sort of world) to get him back.

One other note, if this is any help whatsoever, is there was a chunck of the book to which she was taken and forced to fight in a cage against other people, to the death. She was a prisioner there for a long long time, and she was legendary, known as some sort of black bird or what not as her nickname.

If this sounds familiar to anyone (I know it's very vauge, so sorry ><<<<) please hit me up- I really really wanna find this book O>OOOOO

ALSO: if you picture these two pictures mashed together, this is what the cover looks like (minus the girl sillioute in the middle) XDD:

https://kylebstiff.files.wordpress.com/2013/04/red-desert-1-pcvzxrvlh4-1024x768.jpg 

http://wallpaperswide.com/desert_sand-wallpapers.html