?? about " The Backwoods"?? I'm a bit confused-?

The Spanish men say their Sister is a good woman and it wasn;t her fault( or something like that), so was the main one her Father and her Uncle? Is that why she was deformed? Did the Sister get raped and have in inbreed child out of incest and out of wedlock, so they locked the girl up so know one would know. Also the guy at the end seemed to love her, so why treat like a wild dog? One more ? - who was shot at the end?