Originally posted by jab1617 Thanks everyone for the advice. I agree, it is definitely a depth of field issue and I will patiently try to persuade the wife to use the Av or Tv modes.
What is the shutter speed and ISO setting the green mode automatically choose when your wife shoots indoor? I suspect that Av or Tv mode is not a solution here as the indoor lighting was probably not enough for fast shutter speed (1/50 or faster). F/2 or F/2.4 was a probably proper exposure even if you were the cameraman. I think what you need to teach her is to properly autofocus on her subject by pressing the shutter botton half way, recompose without unlocking the focus, and shoot.
My wife, who does not want to change lens, always keeps a DA 18-50mm on her K100D Super and takes fine photos with Program mode and sometimes with the onboard flash. Your ultimate solution might be just giving your K100D and the kit lens to your wife and buying another body for you
Anyways, I would recommend getting an external flash if you don't have one yet.