I flew for an airline in the US, Champion Air, which at one time had in the ops specs, that family members could ride the jumpseat. I took my wife from CLT to MEM and back a week later (I was based in Memphis). The trip up to MEM climbing thru FL180 I reached up and flipped off the lights, my SO said Climb Check complete, so I engaged the autopilot, told my FO he had the A/C. I turned around to ask my wife what she thought and she was white as a ghost. I said "Honey are you ok?". She said I cannot believe we're doing this and you are in charge of all this. I said what do you think I have been doing all these years???? A couple of years later I had the pleasure of having my 12 year old niece with me on the JS. It was the time of her life!!!! All this was pre 9/11 obviously.