Unless already mentioned, try these settings:
Got to Menu 1 - Creative Style - Scroll down to '1 Portrait'. 'Portrait' is the default setting for this first of the 'switchable' creative styles -- the ones prefixed with a number.
Shift right so that 'Portrait' is highlighted bottom left of the right hand panel. Now use the up and down shift to find any of the Creative styles -- including 'Deep', 'Clear' and 'Light', which can't be found anywhere else.
Set your creative style to DEEP and set as follows:
Brightness: +/- 0
Contrast: BLANKED OUT as Zone Matching has been adjusted from zero
You should now be good to go for optimal JPEG output. DO NOT use AUTO for any of the main settings, rather select WB: Daylight, matrix metering, spot focus, JPEG quality = Fine, image size = Large, Mode = (A) Aperture. This way you have a decent amount of pre-sets that are perfect for normal daylight use. Your son then controls depth of field (DoF) via the control wheel and the shutter speed by the camera. You son can become more creative with his shooting by separating the subject from the background. One great function is the Depth of Field button. Look through the viewfinder whilst holding the button in and turning the control wheel to adjust aperture. He'll hear a shutter sound and see the level of DoF being applied though the viewfinder so he can then select the appropriate aperture knowing what will be in focus or not. It's not a perfect system, but it does work very well.