Having had a few bad experiences, my No.1 suggestion for flying with passengers, especially novice/nervous passengers, is: Ensure that they have a GOOD HEADSET. I.e., don't borrow whatever cheapo spare headset the flying school or club happens to have on hand.
Your wife will not enjoy the flight, and will lack confidence in the entire endeavour, if her headset doesn't work (and fit) well. Trust me, you want her to relax and have a good time (first impressions count for a lot), and you can really jeopardize this if she has a crummy headset.
Finally, here is a link that may help you:
www.avweb.com/articles/lounge/tpl0020.html
Have fun,
MLS-12D
