Please ignore the thinly veiled contempt and sarcasm, not all MorphOS users are like that. I'm sure Grandma is just having an off day.
Were you connecting to your monitor via HDMI by any chance? DCC with HDMI TVs isn't always as automatic as one would expect but it's trivial to fix, you just rename a Full HD monitor driver to the auto-detected monitor name and reboot.
I can provide more detailed steps upon request.
