Buy a Spot Messenger. Then you can check in anytime, and she can always see where you are. If you get into trouble hit the 911 button and get the SAR heading your way pronto.
Anytime you hit the check in button it will send an email and/or text message to your list of friends or family.
Or, you can turn the tracking on and they can see where you are at in near real time. The Spot sends coordinates every 10 minutes.
It's very hand, the cost is reasonable. Most of all it will give your wife peace of mind.