You are married, that means she has to be listed on the policy in order to be covered. Because she is assumed to have regular use of the car, they need to take her driving record and other risk factors into account when they rate the policy. You can have her as the secondary driver of your car, if that is the case, but if you take her off the policy, she probably won't be covered to drive the car when she's in town.
You should explain the situation to your insurance agent and ask if there is a way for you to save money while still keeping her covered when she is in town and driving the car.