Sienna Miller made a public appearance in West London on Thursday, attending the Debute pop-up shop opening party. The 44-year-old actress, who recently welcomed her third child, wore a white summer dress paired with black sandals and a Prada straw beach bag. She was seen with her blonde hair in a casual updo, accessorized with sunglasses. Miller was joined at the event by Elena Ora, sister of singer Rita Ora. Ora wore a black lace dress with white heels and a matching lace bag. This marks Miller's second public outing of the week. She also attended the Serpentine Gallery Summer Party on Tuesday. At that event, she wore a silk dress with a fur-lined coat, despite London temperatures nearing 40 degrees Celsius (104 degrees Fahrenheit). Miller attended the Serpentine Gallery party approximately six weeks after giving birth. Miller welcomed her third child in May, her second with partner Oli Green. The couple also have a daughter born in January 2024. Miller's elder daughter, Marlowe, is 13 and from her relationship with ex-partner Tom Sturridge. Earlier in June, Miller's sister Savannah confirmed that the actress is engaged to Green. Savannah, a fashion designer, described Green's proposal to Miller, who is 44, as "beautiful" and expressed happiness for her sister. Rumors of the engagement began circulating last week after Miller was seen wearing a diamond ring on her wedding finger during a trip to Barcelona. This would be Miller's fourth engagement, though she has not previously married. Friends of the couple have indicated that Green, 29, has wanted to marry Miller for some time. A friend described them as "ridiculously in love" and "having such a giggle together." Miller has not yet publicly shared the sex or name of her third baby.