Maximum "Max" is an avian, genetic experiment created by a mysterious organization called "The School". She and her "flock" eventually escape, but are always on the run. But what they don't know is that Max may not be a freak, but the key to humanity.
The Flock
Fang (14)
Iggy (14)
Nudge (11)
Gazzy (7)
Angel (6)
There is also an manga (a comic-sort-of-thing) of this book series if you want to see it with pictures. Unfortunately, the manga only has covered the first 2 and a half books now and the production is pretty slow, but it's still worth a look.