News outlets reported Friday that the 29-year-old actress and 39-year-old actor welcomed their second child in New York.
The Shallows star and Reynolds met on the set of Green Lantern in 2010 and married in Mt. Pleasant, S.C., in 2012. The couple are already parents to 21-month-old daughter James, and confirmed they were expecting again in May.
"I feel good," the actress said on Live! with Kelly in July. "[This pregnancy has been] much easier. A lot faster. You get bigger faster, too, which has been nice to try to fit into clothing strategically."
Lively had previously told the Today show that she and Reynolds hope to have a big family, joking that they're "officially breeders." She said in the July issue of Marie Claire that her family is the No. 1 priority in her life.
"All my eggs are in one basket, and that's my family. That's where my heart is. That's where my everything is," the star declared. "My family: That's the thing I feel most protective of and the thing that I feel is the most exposed when I feel exploited."
Lively is known for playing Serena van der Woodsen on Gossip Girl and will next star in All I See is You with Jason Clarke. Reynolds is slated for Deadpool 2 and the comedy-drama Truth in Advertising.