In Scotland (which is north of northern England :-), if used about a living creature, “puir scunner” would be, approximately, “poor barstid<-[dodging the nannybot]”, “luckless begger”, etc.
They are twin brothers in Transvaal who were greatly disabled, cognitively, from birth. They’re thought to have cognitive skill at the 5yo level. They’re also largely mute, possibly because of deafness.
They became world famous because of the photographer who took pictures of them, and because to their physical appearance. If you look them up by their first names (Dresie and Casie) you can see the photos and a little commentary.
They apparently have very cheerful, outgoing personalities in spite of everything, and enjoy their lives. (They might be dead by now, but people who care about them have been very careful to let them live their private lives without exploitation, so they’re probably still alive)
The right size, of course, is the size they are. If she had ears like Driesie’s or Casie’s, poor scunners, that would be cause for a plastic surgeon consult.
Or “cue Jack” perhaps?