Miriam was the bastard child. Her mother was considered an outcast for becoming pregnant out of marriage. She had been Jalil's, Mariam's father's, servant. Mariam was raised in an isolated environment by a mother who restricted her activities to protect her but put her down. Her father visited her but was not in her life as much as she had desired. When she tried to be a part of his family, he had her married off to Rasheed. Her husband beat her and treated her brutally. She lost her only child through miscarriage and could no longer conceive.
Laila was raised by an modern mother and educated father with siblings. Sheattended school and had freedom that many Afghan women and children did not experience. Her father was loving and kind toward her. She had a lover by whom she became pregnant. Her parents were killed in a bombing. Alone and confused, she was taken in by Mariam's husband and became his wife. Rasheed treats her well, and she bears two children.
Laila's upbringing makes her the stronger of the two women. She has the courage to try and escape the household of her husband. Her loving nature also helps Mariam to experience love and family through Laila and her children. Lalia's effort to help them escape leads to brutal punishment for Mariam at the hands of Rasheed.
Eventually their differences lead to a conflict that ends in Rasheed's death and Mariam takes the blame. The larger theme is the friendship that these two very different women experience as they, become family who are deeply loyal to one another.