Each sister in Shanghai Girls believes that her parents loved the other sister more. Who is right about this? Why?

Lisa See’s novel Shanghai Girls centers on the characters Pearl and May, sisters who have a complex, loving yet conflicted relationship. Pearl is the protagonist and older sister. She believes her parents favored her younger sister because of her looks. While May is considered more beautiful, both girls are physically attractive. They work as “beautiful girls,” modeling for artists who use their images on posters, calendars, and advertisements. May also believes their parents loved her sister more than her. Because Pearl went to college, May feels jealousy toward her and sees this as a sign of their parents’ favor. These petty jealousies and rivalries stem from the girls’ perceptions of their parents rather than from reality. However, after their father loses his wealth to gambling and their mother is raped and killed, the sisters must cling to each other for support. Even early in the novel, the girls band together in rejection of their parents’ traditional ways by doing modeling work and staying out late at night.
Because Pearl is the narrator, the reader receives her version of the truth. Thus, her impression of being the less favored sister holds greater weight and the shadow of this perceived injustice colors the narrative. Pearl at times seems resigned to her sister being loved more by their parents, even looking on the bright side, saying, “My parents fell in love—total, besotted love—with their younger daughter. This allowed us to retain a certain amount of liberty.” Pearl acknowledges the benefits she too receives when their parents look the other way.