I love The Broken Wing. It will make for good sequel title when it becomes a movie. ^_^
The Broken Wing. Love that one!!
I went with Betrayed by Duty. I found absolutely NO books with that title, and it would seem to fit (from a certain point of view) with the basic theme established by the title of the first book.
Went for The Broken Wing. No particular reason why I did. Maybe because I like "The..." titles. Having a quick look on GoodReads (as I'm on that site at the moment) I see there's only a handful of books called The Broken Wing, so it's not like you'd be competing against hundreds of books with the same title.
Best wishes with whatever you decide to go for. :)