Meryl Streep Is Becoming a Grandma for the First Time

Congratulations are in order for Meryl Streep. No, she didn't win another Oscar (yet—but that last scene in Mamma Mia! Here We Go Again was pretty great so who knows? This could be Oscar number four). This happy news is much more personal: Meryl is about to become a grandma for the first time.

The three-time Oscar-winner's oldest daughter, actress Mamie Gummer, is expecting her first child with fiancé Mehar Sethi, her rep confirmed to Page Six this weekend.

Mamie, 35, is the second of Streep's four children with her husband, sculptor Don Gummer. Mamie's siblings are Henry Wolfe Gummer, 33, Grace Gummer, 32, and Louisa Gummer, 27.

Mamie, who got engaged to Sethi in August, was previously married to actor Benjamin Walker but the pair split in 2013 after two years of marriage, according to The Hollywood Reporter.

This will be Streep's first time becoming a grandma IRL, but she's played the part on screen before. She'll play a grandmother in the second season of HBO's hit Big Little Lies, in which she stars as Mary Louise Wright, mother of the late Perry Wright (Alexander Skarsgard) and mother-in-law to Celeste (Nicole Kidman). If Mary Louise is anything like her son, she's going to be one scary lady.

Even though Streep hasn't done grandma duty before, we know she'll play the part effortlessly (like she does literally every part). And Mamie says taken lots of lessons from her famous mom over the years as well.

"Well, I’ve been watching her my whole life," Mamie told The Telegraph in 2015 of learning from her mother. "Not just how she act—if she has a secret to her success, she hasn’t passed that on—but how she behaves and interacts with the world; like any kid does with a parent."