To support my wife I am thinking about following her diabetic diet with her - is there any reason not to?

Wonderful! What a wonderful husband! your support will make it much easier for her to control her diabetes. And it might make you healthier, too, because a diabetic diet is basically a healthy, well-balanced diet that anyone can follow safely.
Absolutely none. I like to think there is really no such thing as a "diabetic diet". It is the same low carb, healthy diet everyone should be on.
Diabetic diet. The diabetic diet sponsered by the ada is a healthy diet. As long as you do not have any medical problems that require so other diet it would probably be safe and beneficial for you to support your wife and go on her diet. This is a general answer. Specific diet advise should be discussed with your doctor.