Laura and Mary attend their first day of school in Walnut Grove. There they meet Nellie Oleson, who condescendingly refers to them as "country girls". Not having been to school before, Laura makes an extra effort with her studies. When she is unable to write the words for an essay about her Ma, she recites it directly from her heart.
Comment: When viewing later episodes, it's amazing to see how much the will grow during the course of the series.