Here's what I'd do...
- Smooth air. Good weather.
- Take them through a through pre-flight
- Keep the first flight short. I'd say 15 minutes tops. There's nothing wrong with leaving her wanting more.
- No hotdogging.
- Now this will probably spark some controvery, but keep the emergency proceedures to a minimum. Anxiety is the mind processing all the things that COULD go wrong regardless of solutions to said problems. So going over in detail what to do in case of fire, smoke, forced landing, and the rapture is likely to fuel her anxiety not ease it. Even though it will increase your workload a bit in an emergency you can always walk her through openning the door IF something happens. This is how I'd handle it anyway.
- Don't assume that she wants to learn how to fly. Keep the coversation light. Tell her to ask any questions that she has. Some people don't like to talk a lot when they're fearful, because they focus their mental energies into calming themseleves. If she doesn't want to talk do push it. Talk with your buddy and monitor her.
- Keep a sick-sac in your pocket just in case, but don't even mention airsickness. Most airsickness is more mental than physical.
- I'd put her in the right seat if she's cool with it. That way she can see the instruments and confirm that the plane is still flying.
- She should probably go with a very experienced CFI for her first flight....unless of course you're an experienced CFI.
The last thing I'd say is don't press the issue. If she doesn't want to fly then don't make her. Let her spend time watching the planes take off and land at the airport. After a while she may actually decide that she's being irrational and ask to go up.
My two cents.
Naunga