Even stipulating that Jews made diapers during WWII, they would not have been available in America, except to specialty markets which, most likely, would have known exactly what they were. (Likely, diapers from the "Old Country".) In fact, hausfraus would have made their own diapers by cutting up old bedsheets and the like.
In the real world, in 1940 would have you bought a Ford, even knowing of Henry Ford's love and respect for Adolf Hitler? Assuming, of course, that you were in the market for a new car in 1940.