All three of them untwinned, lonely, alone together.
-- Narration ("Dosas")

Importance: This line of narration refers to Elsie, Blaise, and Olivia. After Blaise formed a romantic/sexual relationship with Olivia, his wife Elsie remained devoted to him. Elsie believed that all three of them were essentially grasping for connection. however, she is ultimately faced with the bitter truth that Blaise simply fell out of love with Elsie and fell in love with Olivia. Thus, Elsie is the only character of the three to be isolated at the end of the story.

Tears of anger, too. Of being robbed of money that took years to save, and seeing her dream of owning a house disappear along with the children she and Blaise would never have.
-- Narration ("Dosas")

Importance: This line of dialogue addresses some of the destructive consequences of Blaise's actions. Elsie gave Blaise nearly all of her savings because Blaise falsely claimed that Olivia was kidnapped...