What is the theme in Wild Swans: Three Daughters of China by Edna St. Vincent Millay?

Love of family is the main theme of the book. Though Chang Shou-yu is demanding of his family, there is love among the siblings and their parents. When Chang Shou-yu is imprisoned, Jung and her brothers and sister take turns traveling to visit with him. The trips are difficult as there is no established transportation. As a rule, Jung and the others catch a ride on whatever truck happens to be going the right direction, often walking miles in order to reach their father. Though they all have difficult lives of their own, they give up their time to stay with Chang Shou-yu. Jung says that they are all concerned about his mental well-being and feel that he needs to be surrounded by loving family.