Sienna Miller enjoyed a night off from parenting duties as she attended Abigail’s Party at the Harold Pinter Theatre in London on Wednesday night.The actress, 44, who welcomed her second child with fiancé Oli Green in May, looked in great spirits as she put on a stylish display in an embroidered white shirt. She paired the shirt with a flared pair of blue denim jeans, black slip on shoes and orange lens sunglasses. The star was joined at the event by presenter Gaby Roslin who brought a pop of colour in a bright orange shirt and blue lens shades. Meanwhile Leigh Francis, otherwise known as Keith Lemon, made sure all eyes were on him in a fun T-shirt printed with hedgehog toys and a straw sun hat. Abigail’s Party has returned to the West End for a strictly limited run , starring Tamzin Outhwaite as Beverly in the 1977 hit play. Sienna Miller put on a stylish display in an embroidered white shirt as she enjoyed a child free night at Abigail’s Party at the Harold Pinter Theatre in London on Wednesday night She paired the shirt with a flared pair of blue denim jeans, black slip on shoes and orange lens sunglassesSienna’s outing comes after she appeared to share a major clue that she welcomed a son with her fiancé Oli earlier this month. The star seemed to confirm the couple have welcomed a son as she posted a snap of the three-month-old lying in a pram with a blue heart over their face. Meanwhile a makeup free Sienna read to her daughter, whose name has never been announced, as she covered her face with a red heart. The star also shared a close up snap of Oli, 29, as the family enjoyed a summer holiday together. Sienna also has 14-year-old daughter Marlowe with her ex Tom Sturridge. She announced she had welcomed her third child in May, simply saying: ‘It’s happened. I have a tiny baby next door.’ Sienna announced her third pregnancy by revealing her blossoming bump at the star-studded Fashion Awards in December.In May, she said that she’s surviving on ‘very little sleep’ as she opened up on returning to work just three weeks after giving birth while appearing on The Tonight Show With Jimmy Fallon. The star was joined at the event by presenter Gaby Roslin who brought a pop of colour in a bright orange shirt and blue lens shades Angela Griffin opted for an all blue co-ord and chunky trainers Actors Michael Brandon and Glynis Barber enjoyed the night out at the theatre Actress Sarah Parish wowed in a deep blue wrap dress and brown belt Daniel Mays and his wife Louise Burton beamed ahead of the show Actress and presenter Tina Hobley opted for a striped green and white shirt and pale yellow skirt Radio presenter Emma B looked stunning in a white and black polka dot dressDuring her appearance on the show she opened up about the transition of having another child and spoke about her nightmare flight over to the US to promote new action movie Jack Ryan: Ghost War.Sienna said: ‘It feels like stringing sentences together is a bit challenging. 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.’Asked by the host which of her children are tougher to look after, 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.’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.’