When Penny was 12, she rebuilt a tractor engine all by herself ("The Big Bran Hypothesis"), started dating at the age of 14 ("The Robotic Manipulation") and in high school, nearly became pregnant ("The Staircase Implementation") and had an active sex life that she defines as being popular.
Leonard's little make out session at sea, makes their marriage have a rocky start, but they quickly reconcile though they don't move out of Sheldon's apartment (because of Sheldon going through a bad breakup, and due to Sheldon's abandonment issues).At the end of the season, when it's revealed that everyone is upset about not being part of the wedding due to their elopement, Penny suggests having a redo wedding ceremony.Wyatt (father) Susan (mother) Randall (brother) Unnamed sister Unnamed brother-in-law Unnamed paternal grandfather Unnamed paternal grandmother Unnamed maternal grandfather Unnamed maternal grandmother Unnamed nephew Unnamed male cousin Zack Johnson (ex-husband) Mr. She lives in Apartment 4A with her husband Leonard Hofstadter across the hall from Sheldon Cooper, and Amy Farrah Fowler who live in apartment 4B where Penny used to live. Johnson (ex-sister-in-law) Leonard Hofstadter (husband) Alfred Hofstadter (father-in-law) Beverly Hofstadter (mother-in-law) Michael Hofstadter (brother-in-law) Unnamed sister-in-law (via Leonard)Unnamed brother-in-law (via Leonard's sister)Possible sister-in-law (via Michael) Penny Hofstadter (née "Unknown") is the series' first and always main female protagonist.In the episode finale "The Monopolar Expedition", Penny wishes Leonard wasn't going to the North Pole When the guys return from the North Pole, Penny has missed Leonard enough that she expresses her feelings for him and they date for most to the season.
Penny introduces her friend Bernadette to Howard as part of a Girlfriend Pact made between Howard and Leonard.In "The Cohabitation Experimentation", Amy's apartment suffered water damage, was uninhabitable and she needed a place to stay.Sheldon and Amy started a five week experiment to see if they could manage living together and moved into Penny's old apartment, Apartment 4B.It turned into a permanent arrangement in "The Veracity Elasticity". Originally, two different female leads were written for the Pilot episode.The unaired pilot episode had an alternate version of the female lead named Katie.That marriage was annulled in "The Thanksgiving Decoupling".