I have flown over 80 EAA Young Eagles and maybe 15 or so parents. I walk everyone through the preflight. Announce the name of the part or ask them if they know what it is, show them the fuel, engine, lights. Explain lift so a school kid can understand. By the time we mount up, most are ready to go. I have only once bailed out because the child was too scared; having taxed, run up, and called ready to go. This, in my opinion, was the spoiled child syndrome as Nana and Dada were in the back
I always offer a trip around the airport and a landing if any of this makes them uncomfortable or ill. Once the engine is started, I walk through all the things I'm doing and why. The taxi out includes a discussion of the airport signs, lights, and painting. I'll do the run up, emphasising the dual mags again.
Once in the air, I ask if everyone is okay, how they are feeling, and if they want to return. If not, then we're off for a 20 minute flight. Any rough air encountered, I make a joke about speed bumps and then explain why they happen. If turbulence is really bad, I will slow down to 85-90 knots. Speed tends to increase the effect of turbulence. On these YE flights I walk them through turns, climbs, and descents. Of all of them, I've only had two child pukers and one adult.
On the other hand, if it is your wife, tell her you still wear the pants in the family. Get in, sit down, and stfu.
By the way, dramamine works wonders. A friend of mine would always take it before flights. She would be asleep 20 minutes in the air. Then it was peddle to the metal, full military power, pour on the coals, max rental power. Turbulence wouldn't wake her.