Thank you for answering my question, Sensibility, and I also agree with the following posts. Grace never seemed to look different (for a long time), nor did she ever take a bad picture (even though she was short-sighted, so there goes an explanation for her grand-daughter's propensity's to make faces). Was it self-control ? Had she read Chanel's injunction to always dress (and by extension I suppose, look) as if you were going to meet the stranger in your life (who would become your soulmate) ?
Still, I wonder how she would have looked with very short hair. Every actress, even in those days, seemed to have gone through a "let's cut my hair very short" phase. Was her face too square to bear it ? A computer would tell us !