Fashion designer Stella McCartney, 38, and publisher/husband Alasdhair Willis are expecting a fourth child in late autumn, a representative for McCarthey confirms to Women's Wear Daily.
The couple, who wed in 2003, has two sons, Miller, 5, Beckett, 2, and a daughter, Bailey, 3.
She "loves the idea of having a close-knit family, just like the one she grew up in," a source told the UK Daily Mail. Stella, daughter of Beatle Paul McCartney, has two half-sisters; Heather and Beatrice, plus sister Mary and a brother, James.
McCartney recently collaborated with Disney to create an Alice in Wonderland-inspired jewelry collection which features Swarovski crystal accents.