Carey Mulligan quietly announces arrival of her and Marcus Mumford's third child

Carey Mulligan and Marcus Mumford have welcomed their third child.

The couple announced the news in typical low-key fashion, with a Vogue journalist casually writing about the baby’s arrival in Carey’s latest cover story.

The interview, which appears in the November issue of the American version of the glossy, was conducted when she was six weeks postpartum.

A line added to the Instagram cover reveal also notes it “predated the SAG-AFTRA strike”, which began in July.

As per the publication, the Promising Young Woman star entered “a London coffee shop with a bemused gesture at the yellow diaper-leak stain streaked across her blouse”.

She then said to her baby: “I’m going to change you, and then we’re going to find mum another shirt.”

No other information was added.

Carey, 38, and Mumford & Sons frontman Marcus, 36, wed in 2012 and have daughter Evelyn Grace, seven, and five-year-old son Wilfred.