My poor Wife watched me get hit on a ride. She told me it was the worst thing/feeling she had ever seen and had no idea if I was even alive afterwards. She sold her road bike right away. I sold one of my road bikes to fund the purchase of a CX bike and I have mainly stayed off the roads and stopped going out for regular long rides alone. It has changed our lives. Things that have helped her are time and keeping busy when I am out for any sort of ride. You cannot really change how your spouse feels but you can take an interest in your safety and work through her fears together.