Stephanie works as a doctor and highly distinguished surgical resident at Fremont Memorial Hospital. She is introduced in season 2 when Howard tries to seduce her and allows her to drive a Mars Rover.
Instead, Stephanie meets and falls for Leonard, and the pair ends up dating. Stephanie moves all of her belongings into Leonard’s apartment, and Leonard soon ends their relationship through a text message.
Aarti Mann as Priya Koothrappali – Then
Priya plays the part of Raj’s younger sister. She is a law student who we meet during the 4th season. She dates Leonard, and the two don’t tell Raj, who eventually finds out.
Priya agrees to continue to date Leonard under the condition that he cuts off contact with Penny. When Priya’s parents find out about the relationship, they are extremely disappointed and force her to return home. The couple has a long-distance relationship for some time, ultimately finding it frustrating and breaking their loyalty to one another.
Aarti Mann as Priya Koothrappali – Now
The actress has been cast in several TV series since TBBT. She played Dr. DaSilva in the rom-com drama "I’ll See You in My Dreams," as well as María Monroe in "Suits" and Agent Laura Kenney in "Scandal."
Recently, she played the part of Holly Harner in an episode of "Grey’s Anatomy" and filmed a drama called "Love Sonia," playing the part of Jiah.
Sara Rue as Stephanie Barnett – Now
Sara has been cast in multiple TV shows since her role as Stephanie. She played Kim Sallinger in "Malibu Country," Brenda in "Rules of Engagement," and Candace in "Mom."
She's also had regular roles in the TV shows "A Series of Unfortunate Events," "American Housewife," and "B Positive."
Margo Harshman as Alex Jensen – Then
Alex is pursuing her Ph.D. in Caltech Physics and works as Sheldon’s assistant. Sheldon often gives her tasks that are unrelated to their research.
Alex wants Leonard and asks him on a date, but Leonard says no because of his loyalty to Penny.