Jacob Have I Loved (1989)

Jealousy eats at Louise. Like Esau, Louise is a twin, a few minutes older than Caroline, who, like Jacob, is the family favorite. Blond, pretty, with a voice like an angel, Caroline is selfish. Louise is plain, brunette, unappreciated, and hard-working, crabbing and oystering on the Chesapeake Bay island where they live, the money she earns paying for Caroline's voice lessons. In her seventeenth year, between the Christmases of 1941 and 1942, with the help of an old sea captain who's fought his own demons of bitterness and anger, Louise must get past her jealousy and figure out what it is she wants, what it is that she loves.