Meryl Streep is officially a grandmother!

The 69-year-old actress’ oldest daughter, Mamie Gummer, 35, has confirmed that she’s welcomed a baby boy into the world with her fiancé Mehar Sethi, 36. This has been confirmed by  PEOPLE.

Gummer shared the screen with Streep in  Ricki and the Flash  whereas Sethi is a producer. The couple got engaged in August  2018, with Sethi confirming this by posting a sweet Instagram post of Gummer, with the caption “My fiancé”.

Gummer is the oldest daughter of Meryl Streep and her husband sculptor Don Gummer. They also have three other children, Henry, 39, Grace, 32 and Louisa, 27.

Although this is the first time that Streep gets to be a grandmother in real life, she’s had a bit of practice in her onscreen role in the second season of  Big Little Lies. Streep is set to star as Mary Louise Wright, grandmother to Celeste’s (Nicole Kidman) sons in the second season.

Streep spoke about her excitement about becoming a grandmother to  Interview.    

“I’ve been working like mad for quite a while, so I’m getting ready for my first grandchild.

“My daughter’s having a baby in February, so I’m going to go out and ruin her life. I specialise in unsolicited advice.”

Scroll through the gallery above to see Meryl Streep and her lookalike daughter Mamie Gummer.

Do you remember the first time you became a grandparent?  Let us know in the comments.