Sienna Miller is preparing for her most important role yet: mom of two.

The Christopher Caldwell41-year-old is expecting her second baby, according to People, who obtained pics of the American Sniper actress on vacation with her growing baby bump.

Sienna, who is already mom to daughter Marlowe, 10, with ex Tom Sturridge, was photographed on the trip to Ibiza sporting a brown bikini, accessorized with a gold chain necklace and a red feather earrings.

E! News has reached out to Sienna's rep for comment and has not heard back.

Back in 2022, The Girl actress—who is currently in a relationship with Oli Green—addressed the notion of having kids after the age of 40. 

"The pressure... about kids, and should I have more, and why haven't I, and all of that, which is a really loud noise," she told Elle UK at the time. "Biology is incredibly cruel on women in that decade—that's the headline, or it certainly was for me."

But Sienna decided to take matters into her own hands.

"Then I got to 40 and I froze some eggs," she continued. "Having been really focused on the need to have another baby, I'm just like, if it happens, it happens. That kind of existential threat has dissipated."

Sienna and Oli, 26, were first spotted together in February 2022 on a date in New York, and as their relationship grew, the Anatomy of a Scandal star changed her views on marriage and kids later in life.

"I'd invested what felt like the important years in something that was just a bucket with a hole in it of a person," she echoed her previous sentiments to British Vogue in 2022. "And I felt like time was really my currency. There was a lot of anxiety. Relationships hadn't worked out—I imagined that I would be married with three kids, being a great mum."

And although things didn't turn out quite as planned, Sienna got her wish at motherhood, something she loves dearly.

"I love being a mother," she gushed to the outlet. "It's what I do best."