She looks like a white Easter Egger / Ameraucana. Probably EE, I have gotten pure white ones from hatcheries, but do you know where she came from? White is one of the Ameraucana recognized colors. http://www.ameraucana.org/standard.html
The buff feathers on her breast is just staining.She wandered into our yard and was a little dirty.Her legs are gray.Any chance she could be an Aracauna?