Sophia Auld is important in Frederick Douglass's narrative in a few ways. First, she begins to teach Douglass to read, and her instruction, though stopped by her husband, starts Douglass down the path to literacy. Learning to read is important to Douglass because it helps him understand the intellectual arguments against slavery (though he already understands how hideous slavery in a personal way), and literacy also helps Douglass by providing him with skills he can use when he is a freedman. Therefore, he has more confidence and greater will to escape to the north. When Sophia Auld's husband becomes enraged upon hearing that she is teaching Douglass to read, Douglass understands the power of reading and pursues learning by bribing local children to teach him his letters and through other means.

In addition, the character of Sophia Auld is symbolic of the way in which slavery degrades slave owners. Douglas paints her as sympathetic at first and then shows the ways in which slavery makes her into an unsympathetic and immoral woman. One of Douglass's purposes in writing his narrative was to show Northern whites the ways in which slavery degraded white slave owners, and he does this through his portrait of Sophia Auld and her trajectory from being a sympathetic white woman to becoming an immoral slave owner.