She had a long career starring and co-starring in films , playing Polly Benedict during the 1930s and 1940s in the Andy Hardy series , and as Scarlett O'Hara 's sister in the film `` Gone with the Wind '' ( 1939 ) .
She playied Polly Benedict during the 1930s and 1940s in the Andy Hardy series . She played Scarlett O'Hara 's sister in the movie `` Gone With the Wind '' ( 1939 ) .