The Cleland's
The Cleland family seems to consist of:
Wade Jnr, who gets stabbed in the head by Dwight,
Teddy, who gets his head blown off by Dwight's friend Ben,
Carl, who Dwight kills first in the final shootout,
Hope, who Kris accidently kills in the final shootout,
Kris, who Dwight kills in the final shootout,
William, who Dwight lets live as he says he's actually his fathers child,
Wade Snr, who died of cancer before the films events begin.
Kris the older of the two woman is listed as being the cousin of the other siblings. So what of the mother that Dwight's father had an affair with?
Lastly IMO a better ending would have been seeing William driving off in Blue Ruin.