Kaley Cuoco's Sister Briana Will Appear Alongside Her In 'The Flight Attendant'

Kaley Cuoco's upcoming HBO Max series is turning into a family affair. On Thursday, Deadline reported that The Big Bang Theory star's younger sister, Briana Cuoco, has landed a recurring role on The Flight Attendant.

Briana, 31, has been cast as a character named Cecilia. Unlike Kaley, 34, she won't be playing a flight attendant; Cecilia is an "ambitious assistant" to an unnamed character. Interestingly, Pop Culture reports that Briana once worked as a real-life personal assistant to her famous older sister.

Cecilia is described as having an obsession with organization, which may help her excel at her job. She also enjoys "eavesdropping on calls," but it's yet to be determined whether this habit is helpful or harmful in the turbulent, mysterious world of The Flight Attendant.

It's also unclear how much, if any, interaction there will be between Briana and Kaley's characters on the darkly comedic series. Kaley is playing the lead role of Cassie, a flight attendant who finds herself facing a killer of a conundrum after she wakes up with one hell of a hangover — and a dead man in bed with her.

She doesn't recall how he got there or how he died, and she's not even in the right hotel. The series is based on the New York Times best seller of the same name by author Chris Bohjalian. In addition to starring on the show, Kaley is also an executive producer.

Briana Cuoco celebrated her casting on Instagram, where she shared a screenshot of the Deadline announcement.

"Christmas came early," she captioned the post.

"Epic," Kaley wrote in response to the news.

As previously reported by The Inquisitr, Kaley Cuoco recently spent some time in Bangkok filming scenes for The Flight Attendant. She was joined by a large group of cast members that included Game of Thrones star Michiel Huisman and Do the Right Thing actress Rosie Perez, who plays one of Cassie's fellow flight attendants. She's the leader of Cassie's team, and she's also a close friend and confidant of the possible killer.

In her Instagram stories, Kaley has revealed that she's now back in New York filming, and it looks like Briana might be staying with her at her temporary home in the big city. Kaley shared a snapshot of the two hanging out together and wearing matching all-black ensembles.

This won't be the first time Kaley and Briana have appeared on a series together. Briana had a small role in a 2013 episode of The Big Bang Theory titled "The Tangible Affection Proof." She played a woman named Gretchen, who was responsible for breaking up Kaley's Penny and one of her exes.

In addition to landing small roles on various other television shows, Briana Cuoco is a talented dancer, choreographer, and singer. She even competed on Season 5 of The Voice as a member of both Blake Shelton and Christina Aguilera's teams.