Jamie Lee Curtis congratulates movie daughter Lindsay Lohan on the birth of her first child

Jamie Lee Curtis is continuing to express her love for her screen daughter Lindsay Lohan IRL.

On Monday Curtis celebrated the birth of Lohan's first child with a heartwarming Instagram post, sharing a photo of herself and Lohan from the days when they were costarring as mother and daughter in the 2003 remake of Freaky Friday.

"Magic Monday!" Curtis wrote. "My movie daughter just made me a movie grandmother. Blessings to Lindsay and Bader for the birth of Luai!"

Lohan and Curtis starred in Freaky Friday as Anna and Tess Coleman, a teen and her mom who accidentally swap bodies thanks to a fortune cookie in the days leading up to Tess' wedding to Ryan (Mark Harmon). They both learn to empathize with one another by living in the other's shoes.

Both Lohan and Curtis are attached to a Disney-backed Freaky Friday sequel, which Curtis has long been banging the drum for. But she recently told EW that the project is on hold until the Hollywood writers' strike is resolved.

"Stories require writers, and right now there are no writers because they're all fighting for their lives, for their creative lives, for their emotional lives, and for their financial lives," Curtis said, weeks after telling Allure that Lohan could "bring the baby" to set while they filmed. "We're in the middle of a contract dispute. And so, until those writers get paid correctly and protected by the producers that make billions off of them, we will not be able to tell you any more about the Freaky Friday sequel, except that it is happening."

Everett Jamie Lee Curtis and Lindsay Lohan in 'Freaky Friday'

Lohan's publicist confirmed to EW earlier Monday that the actress and her financier husband, Bader Shammas, had "welcomed a beautiful, healthy son named Luai," adding that the family "is over the moon in love."

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Related content:

• Lindsay Lohan gives birth to first baby, names new son Luai

• Jamie Lee Curtis is ready for pregnant Lindsay Lohan to 'bring the baby' to Freaky Friday sequel

• Lindsay Lohan remembers feeling 'so self-conscious' in those Freaky Friday low-rise pants