Zeena Frome and Mattie Silver
Zeena an Mattie are obvious foils. Zeena is nasty where Mattie is sweet. Zeena is sick but Mattie is healthy. Zeena is prematurely old, while Mattie is a flower of youth. Zeena is Ethan's wife, while Mattie is his love. Or at least that's how it is for most of the story. Then all of a sudden, the tables turn. Suddenly Zeena is healthy and Mattie is ill. Zeena seems young and Mattie appears old.