She was petite in stature and enormous in personality. Her fear, I expect, was that her personality would translate into becoming a heavy woman. Her weight was important, almost as important as keeping her children amused, and her carbohydrate aversion kept her from serving potatoes. Potatoes were saved for Thanksgiving, Easter, and Christmas. Otherwise, the only other carb was Minute Rice.
For a non-cook like mama, somehow the convenience of something only taking a minute to cook out-weighed all the danger and fear of the carbohydrate.