Laura Ingalls was portrayed by Melissa Gilbert on Little House on the Prairie television series, and Willie Oleson was portrayed by Jonathan J. Gilbert. They are adopted siblings in real life. Jonathan left show business after the conclusion of the Little House on the Prairie television show.
Melissa Gilbert has said that she is no longer in contact with her adopted brother. In his early 20s, he moved away from California and eventually became a stockbroker in New York City. The reason for their lack of relationship now is unknown, as Melissa has stated she does not know why they are estranged.
Note: the real life Laura Ingalls was not related to the Oleson family nor the families she combined to create the Olesons in the Little House books.