When Penny was talking to her mother about her engagement to Leonard in "The Status Quo Combustion", it was implied that her sister was pregnant when she got married which is later confirmed in "The Bachelor Party Corrosion" where Penny mentions that her water broke at the wedding reception after she and Wyatt started their father-daughter wedding dance.
She also saw Penny's boyfriend's Twitter on her sex life and contacted Penny in "The Tangerine Factor".
In "The Parking Spot Escalation", she is mentioned to have given her sister her first bikini wax using melted crayolas and duct tape. The experience traumatized Penny to the point that she can no longer see a box of crayons without crossing her legs.
Her name was finally revealed in "The Donation Oscillation".
- Paternal Grandfather: Unnamed
- Paternal Grandmother: Unnamed
- Maternal Grandmother: Unnamed
- Maternal Grandfather: Unnamed
- Father: Wyatt
- Mother: Susan
- Sister: Penny
- Brother: Randall
- Uncle: Unnamed
- Cousin: Unnamed
- Husband: Unnamed
- Possible son/nephew: Unnamed
- Brother-in-law: Leonard Hofstadter
- Lisa, her husband and possible son/nephew were, unfortunately, absent from Leonard and Penny's wedding redo. It is unknown why. Either the writers forgot Penny has a sister, a brother-in-law and nephew or because of a limited episode budget for actors and actresses.
- She could have had a big fight with penny, so they are not on speaking terms
Lisa the mystery.