Rose of Sharon is Tom's younger sister. She is married to Connie Rivers, and has been staying with his family. She is pregnant with their first child, and "she [is] all secrets now she [is] pregnant, secrets and little silences that seemed to have meanings. She [is] pleased with herself, and she complain[s] about things that [don't] really matter" (13.52). She dreams of living comfortably in California with her husband, going to see movies on the weekends, and buying pretty clothes for her baby. She worries constantly about her baby's health, and relies on her mother for information. While the family encounters obstacle after obstacle, Rose of Sharon can't seem to shake her self-centered perspective of the world.
In Rose of Sharon's world, the kitty litter really hits the fan when Connie disappears after the Joads settle in their first Hooverville. Rose of Sharon doesn't know what she'll do without him, and suddenly realizes the weight and responsibility that a new baby brings.
Throughout the journey, she often begrudgingly helps her mother with cooking, cleaning, and other domestic chores. As the Joad's situation worsens, and as she watches her family scramble for food, Rose of Sharon begins to wake up and smell the grapes. When she is nearly nine-months pregnant, she insists on helping her family pick cotton. As a result, she gets sick, and quickly goes into labor.
Rose of Sharon's baby arrives stillborn during a great flood, and Uncle John dumps the baby's corpse into the raging river. We expect Rose of Sharon to be devastated by this second, and most heart-wrenching, loss, but instead she rallies. She uses her breast milk (which otherwise would have been used to feed the new baby) to help nurse a half-starved man back to life. The act of nursing a grown man is definitely something we'd never expect Rose of Sharon to be able to do, but she does so willingly and almost happily. As she nurses the man, a "mysterious" smile creeps across Rose of Sharon's face, forming the final image of the entire novel. What is in this mysterious smile?