Character Analysis
Sara's kind and hospitable, despite being dirt poor and with a baby to care for. Her husband was killed in the fighting, and she has very little, but she's willing to share it. Though she has little reason to hope, she sings to her baby, and in the process gives Inman some hope as well.
In addition to being a likable character in her own right, Sara also plays some other roles in the story. She helps Inman soften a bit, literally and metaphorically. She washes his clothes in exchange for his help, and she also convinces him to shave. All that suggests that he's moving slowly back toward settled life in a place, not just the life of a fugitive.
She also shares some tender, though non-romantic, moments with Inman, moments that prepare him and readers for his reunion with Ada. Sara asks him to sleep in the same bed with her but not do anything more, and she sings to her baby with him listening.
These moments show Inman softening, preparing for a reunion with Ada. They're not about romance, for him or for Sara. They both have experienced love with other people, and it's not what they need from each other. But they share humanity in a moment where they can soften after all the hardness survival requires of them.