Actress Sienna Miller was pregnant while filming the entirety of new divorce drama War and reached 35 weeks by the end of shooting.
The 44-year-old British-American star welcomed her third child in April with her partner Oli Green, 29, before the couple got engaged two months later. The pair had previously welcomed their first child together in January 2024.
Miller also shares a 14-year-old daughter, Marlowe, with actor Tom Sturridge, whom she dated for four years until July 2015.
While pregnant with her third child, Miller was filming the television legal drama War, in which she stars opposite Dominic West. The series follows the bitter story of their characters' divorce.
Miller plays Carla Duval, while West, 56, takes on the role of her ex-husband Morgan Henderson. The narrative follows two elite London law firms going head-to-head for victory. West is a veteran English actor best known for portraying Detective Jimmy McNulty in HBO drama The Wire and King Charles III in Netflix series The Crown.
In a new interview, Miller described the shoot as tough due to her pregnancy, explaining that long filming days resulted in her leaving and returning home in the dark.
She starred alongside Phoebe Fox in the series, who was also pregnant during shooting. Unlike Miller's pregnancy, Fox's pregnancy was written directly into the plot of the show. Fox is an English actress recognised for her extensive stage work and roles in screen productions including television series The Great.
Joking about sharing the experience on set with her co-star, Miller told The Observer: "She got in first. We sat together scoffing Freddos in between shots." Freddos are popular frog-shaped milk chocolate bars produced by Cadbury, while The Observer is Britain's oldest national Sunday newspaper, published by Guardian Media Group.
Tiredness and Fashion Struggles
The disclosure comes after Miller admitted earlier this month that she felt like a "lactating heifer" and was struggling to dress her "massive boobs" after being "pregnant or breastfeeding for nearly four years".
In a candid interview, the mother-of-three joked that she was so tired she "doesn't know who she is" anymore as she juggles her professional acting career and raising her brood.
Reflecting on her daily routine and physical changes, Miller admitted: "I have completely lost my fashion sense. I've been pregnant or breastfeeding for nearly four years, and I think something happens to the brain, or you're so f***ing tired, that you sacrifice your identity."
She added: "You're just 'mother'... and not in the Gen-Z way, as much as I would like to be."
Miller further explained her feelings of fatigue: "I'm just really questioning all this, because I'm just so underslept and I kind of don't know who I am. I also have massive boobs, which I don't know how to dress. Anyway, this is far too much information…".
She also told Vogue magazine that on the day of her interview with them she had been up breastfeeding since the crack of dawn, before adding: "I just feel like a kind of lactating heifer." Vogue is an international fashion and lifestyle publication founded in 1892.
Family Connections and Style Advice
During her discussions on fashion, Miller revealed that she often turns to model Alexa Chung for style advice, including guidance on what to wear for the recent Oasis: Don't Look Back In Anger premiere. Chung is a prominent English fashion designer, television presenter, and model, while Oasis is the iconic Manchester rock band known for 1990s hits including Wonderwall.
Chung is the partner of Miller's ex Tom Sturridge, with whom Miller co-parents her eldest daughter. Sturridge is an English actor who starred as Dream in the Netflix fantasy series The Sandman.
Navigating Motherhood and Travel
In May, Miller appeared on The Tonight Show Starring Jimmy Fallon in New York City just three weeks after giving birth. The Tonight Show is a long-running American late-night talk show broadcast on NBC from Rockefeller Center.
During her sit-down interview with the TV host, Miller confessed that early motherhood was exhausting at times, saying: "It feels like stringing sentences together is a bit challenging."
She expanded on the physical toll of early post-natal care: "I'm on very little sleep but I'm madly in love with my baby. It's crazy to be talking words and wearing a dress. What has happened from pajama gate."
When asked by Fallon which of her children were tougher to look after, Miller admitted she previously thought her teenage daughter would be harder to juggle, until a recent long-distance flight changed her perspective.
Recalling the journey with her younger children, she said: "I would have said the teenage girl would be harder to juggle until the transatlantic flight I took yesterday with the toddler and the newborn."
She added: "The toddler now wins hands down. It was an absolute disaster. There's no negotiating. I got to the immigration line and just broke down."
Postpartum Euphoria and Upcoming Release
Miller also reflected on motherhood in a separate interview with Vogue, speaking about the joy of extending her family later in life.
She recalled her initial feelings about having more children: "I'd wanted another baby for so long that my postpartum was just bliss. I had thought, by the time I was 40, that it wouldn't happen. That I'd have my one baby and I kind of made peace with it. It was such a surprise, and it was such a bonus that I was just euphoric. I felt existentially relieved."
Miller first achieved international fame in the mid-2000s following roles in British films such as Layer Cake and Alfie, establishing a prominent screen career alongside her work in theatre and fashion.
Her upcoming legal drama series War will be available for audiences in the UK on October 2 on Sky television and the Now streaming service. Sky is one of the United Kingdom's major subscription television providers, with Now operating as its internet television platform.
