Initially, not much is known about Penny's family, but it is mentioned in the series that her father, Wyatt (portrayed by Keith Carradine,) raised her like a boy, her mother smoked marijuana while she was pregnant with her, her sister shot her husband while they were intoxicated, and her brother is a meth dealer. Her mother, Susan (Katey Sagal), and brother, Randall (Jack McBrayer), are finally seen in the first episode of season ten. Her last name is never revealed during the series. Leonard and Penny date on and off throughout the series which is a big plot point of the show, they eventually marry and find out they're pregnant in the series finale.