The 28-year-old actress is said to be over the moon as a source told People: "Blake is absolutely thrilled and so is Ryan."
The couple are already parents to a daughter James, who is 16 months old.
"Blake is absolutely thrilled and so is Ryan," said a source
Rumours have been swirling that Blake is about to add to her brood. The former Gossip Girl star was pictured filming on the set of her new thriller The Shallows in Malibu earlier this week. Blake plays a young surfer who finds herself in trouble when a great white shark circles her.
Wrapping up in a robe and covering her tummy with a surfboard, the actress seemed to have something to hide. Photos from Blake side-on showed her slightly fuller figure and the smallest hint of a baby bump.
Blake has previously said that she would like to have a big family with her actor husband. The blonde Los Angeles beauty has four older siblings, while Ryan, 39, is also the youngest of four brothers.
The former Gossip Girl star comes from a large family
On National Sibling Day last week, Blake shared a sweet throwback photo of her brothers, sisters and half-siblings. "Yes, our parents are breeders," she joked.
Shortly after welcoming her first child, Blake admitted that becoming a mother is something she's "always wanted ever since I was a little girl".
"I knew I wanted to have lots of kids because I had come from a big family so it was always important to me," she told Us Weekly. "So it's just the excitement of that finally being here."
Ryan has joked that his daughter James is "allergic to sleep"
The doting mum has taken like a duck to water in her parenting role, although her husband Ryan joked that the couple’s daughter was "allergic to sleep" as a newborn.
"Our baby, in particular, is, we think, allergic to sleep," Ryan told Jimmy Fallon on The Tonight Show. "We think that she thinks she's protecting us from the sleep monsters. Like, 'Oh I have to keep them up or the sleep monsters will get them.'"