Fact is, by comparing the expressions on tha faces of both June Bamber and Sheila at the time of thier respective deaths, it becomes obvious that June Bamber was conscious of the fact that she knew what was coming, in that instant before she was killed, because her eyes remained open. Whereas, in Sheila's case, her eyes do not have the same feature of "shock", "horror", "oh my god", "look" - this is because she was already unconscious by the time the second shot was inflicted, in keeping with how DS 'Stan' Jones described her, "as though she was just asleep"...