Sarny's at the age where, though she's working, she's not toiling away from dusk to dawn in the fields like the older slaves. Her work around the farm gathering eggs, helping Mammy with the young ones, and working in the flower beds below the big window on the white house still leaves her plenty of time to listen and learn.
While Sarny's working in the flower-bed, the house women insist on leaving the window open, which allows Sarny to hear them talking about their business. In the absence of a formal education, this is how she learns things, and each day she learns a little bit more.
When it gets dark, as she lies on a pallet at the back of a log house, Sarny thinks about all the things that she's learned that day. She tries to combine them with all the other things she's learned on previous days. Sarny's been doing this for as long as she can remember, and it has enabled her to remember all the parts of her life.
With the notable exception of her birth mother. Sarny wonders what she's like, if her skin is dark or light. She also wants to know what her voice sounds like. But in the absence of concrete knowledge and accurate memories, all Sarny can do is speculate.