After being abandoned by her mother in the Everfree forest, Derpy is taken in by the kind earth pony Mary Doo, who tries to do all in her power to unlock Derpy's inner genius from her seemly broken body and mind. As Derpy learns to communicate she also learns the secrets of the world, makes friends, falls in loves, all on her quest to learn to fly so that she may finally accomplish her life long dream and face her face dark past.
This is a spin-off of Bubbles: http://www.equestriadaily.com/2011/03/story-bubbles.html