rob,
My friend, you sure don't want to bollocks up a teaching session with the mrs.
I've found out the hard way about that. :eek:
I suggest laying out the plan to her in advance....first day of riding the very basics are covered and thats it. Starting, placing in gear, controls, braking, stopping(cover that one several times). Once she can let out the clutch and go, just have her do circles, small circles slowly. Then have her switch directions and figure 8. Once she makes a few of them, ease her in a for a nice stop and say, "lesson over".
The urge to continue for a day of riding will be great, especially if she did well up to that point, but don't do it...save it, trust me on this. It will make her next outing much more enjoyable and she will be very much at ease. Same for kids.
Take your time, the nervous ones need a little extra TLC. :)