“This little baby girl will make us a family of five,” Simpson wrote. “We couldn’t be happier to announce this precious blessing of life.”
She has since been putting her baby bump on display while out in New York City, and also shared a pic on Instagram of her growing belly, writing: “My Baby Love.”
Just months prior to her pregnancy reveal, Simpson joked with ET that she and Johnson "always practice" making babies, and admitted that she was having a little baby fever now that their kids are older.
"My daughter is about to turn 6, May 1st is her birthday, and my son is going to turn 5 on June 30th and it's just like, 'Wait, so this is no longer toddler, this is full-on kid,'" she shared. "My daughter [aready] thinks she's a teenager. My son at least wants to be a baby still."
"We always practice," Simpson added of having more kids. "But it would definitely have to be a miracle."