Monday, Jan. 24 marked the premiere date of “The Gilded Age”, the new period drama starring Christine Baranski and Cynthia Nixon as well-heeled sisters who take in their niece (played by Louisa Jacobson) when her father — their brother — dies and leaves her penniless.

What viewers may not realize is that Jacobson comes from acting royalty, the daughter of three-time Oscar winner Meryl Streep.

Nixon shared a brief video on Instagram of the cast gathering together to watch the premiere, with Nixon and Jacobson joined by some of their “Gilded Age” co-stars. As they raise their champagne glasses, Streep herself glides past the camera for a hilarious cameo.

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“Hi Meryl! Last night’s little @GildedAgeHBO hang with @Louisa_Jacobson, @DeneeBenton and @BenAhlers (and crashed by Louisa’s mom),” Nixon wrote in the caption.

“The Gilded Age” represents the first major TV project for Jacobson, 30, whose only prior screen credit was a small role in a 2019 FX pilot, “Gone Hollywood”, that wasn’t picked up.

In an interview with ET, Baranski — a longtime friend of Streep, and her co-star in “Mamma Mia!” — gushed about Jacobson’s performance in “The Gilded Age”.

“She’s marvelous and I think Meryl will be very proud,” she said.