In Shanghai Girls, Pearl's whole outlook on the world changes when she is raped and left to die. She develops difficulty trusting anyone, yet she also develops a firmness in the face of difficulty and a commitment to doing what needs to be done. She agrees, for instance, to raise May's baby as her own.
Pearl and May's father marries them off to two young men, Sam and Vern Louie, and the girls are to go to Los Angeles to start new lives with their new husbands. May is appalled by Vern and does not consummate her marriage. Pearl accepts Sam, at least to a point. But May is the one who becomes pregnant (and will not tell who the baby's father really is), and Pearl pretends to be pregnant and takes baby Joy for her own. Pearl, however, has been told that the rape has damaged her body so much that she will likely never actually have children of her own. She keeps this secret in order to help her sister. We can see Pearl's strength here and her love.
In Los Angeles, the two young women come under the dominion of their father-in-law Old Man Louie, who seems to be something of a tyrant. He was once rich in China but is now poor in the US, and he makes everyone in the family work. Pearl and May save some of their money, hoping to be able to run away. Yet they actually end up integrated into the Louie family more than they ever expect, and eventually they decide that they cannot leave. They also learn that Old Man Louie's only biological son is Vern. The others are “paper sons,” illegal immigrants who have been “adopted” into the family. Old Man Louie has a compassionate side after all.
Pearl becomes pregnant by Sam, but the baby is stillborn, which causes her still more trauma. Toward the end of the novel, Sam sacrifices himself for the family when immigration officials discover him. Pearl actually mourns him quite deeply, for she has grown to love him.