Thanks everyone for your ideas. We were able to get out of town and rent a cabin in Luray. There's a little pond on the property stocked with bluegill and my wife caught her first fish on a fly and then about 9 more.
One thing I learned is that teaching your spouse to fly fish is about as stressful as teaching your spouse to drive a manual transmission. If I were to do it over again, I'd pay a professional to do both.
At the end of my day, my wife told me that now she wants to catch some big fish. So we're already planning a trip back to fish the Shenandoah.