According to E! Online, the 39-year-old designer and rock royal gave birth Nov. 23 to an 8-pound baby girl named Reiley.
That makes four children for McCartney and industrial-design-minded husband Alasdhair Willis (also the co-founder of Wallpaper magazine), who were already proud parents to sons Miller Alasdhair James, 5, and Beckett Robert Lee, almost 3, as well as 4-year-old daughter Bailey Linda Olwyn.
The Web site reports that McCartney will take a short maternity leave before getting back to her numerous fashion design duties, which, not coincidentally, involve creating a new infant- and childrenswear collection for the Gap dubbed Stella McCartney Kids. (Check out the designs here.)
Many congrats to McCartney and also to "Project Runway"'s Nina Garcia, who recently gave birth to an 8-pound-13-ounce baby boy she named Alexander David.