Fashion designer Stella McCartney is pregnant with her fourth child with husband Alasdhair Willis, Vogue reported Friday.

McCartney, 38, and her British publisher husband already have three children together, two sons: Miller, 5, and Beckett, 2, and a daughter, Bailey, 3.

The daughter of former Beatles member Sir Paul McCartney and his late wife, Linda, launched her own fashion line in 2001.

"Stella loves the idea of having a close-knit family, just like the one she grew up in," a source told the U.K. Daily Mail. "She's a great mum. She has been telling all her friends the good news."