Sienna Miller is expecting a baby girl.

The 41-year-old actress previously announced her pregnancy to the world, and she's now confirmed that she's preparing to welcome a daughter with her partner, Oli Green.

Sienna has actually been battling her own prejudices about being an older mum.

The actress - who already has Marlowe, 11, with actor Tom Sturridge - told Vogue: "I’d love to get to a point where I didn’t feel the need to make a joke of my being older and having a baby, to show I’m in on the joke."

Sienna actually showed off her growing bump back in September, when she wore a two-piece ensemble to Vogue World in London.

The actress has now confessed to feeling anxious about her bold fashion choice.

She said: "I was nervous about the idea of it, but once I had it on, everything else felt boring.

"I was like, I’ll have that photo for the rest of my baby’s life. It’s kind of fascinating to fight your own prejudice against yourself. I’m constantly doing that."

Meanwhile, Sienna previously revealed that she froze her eggs in order to future proof her fertility.

The 'Edge of Love' star - who previously had a high-profile romance with Jude Law - admitted that she felt under pressure to have more kids while she still could.

Speaking to ELLE UK magazine in 2022, Sienna explained: "Biology is incredibly cruel on women in [their 30s] - that’s the headline, or it certainly was for me.

"Then I got to 40 and I froze some eggs. 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."