The character of Nancy Oleson was added to the Little House on the Prairie television show to fill the void left by Nellie Oleson when she got married and left town. The character was more of a mean-spirited version of Nellie and she was adopted by Nels and Harriet Oleson.
Nancy Oleson was portrayed by Allison Balson.
Allison Balson appeared sporadically on television shows and movies after playing Nancy Oleson. However, she has focused more on a music career since she was on the show.