Jenna and Steve— who won the Tony Award for his performance in the Broadway production, Once— announced they were expecting a baby in October 2019, less than a year after they sparked romance rumours.
"Becoming a mother is quite simply the absolute best most incredible thing that has ever happened to me ?," she wrote captioned an Instagram photo showing the star cuddling her daughter Everly while her bump was on full display.
"@stevekazee you are a gift from above and I couldn't be more excited to be expanding our family together...! Thank you guys for all the love!!"
Steve penned his own heartfelt note on Instagram, sharing his love for his gorgeous partner while also shouting out Everly.
"I can't even begin to describe the feelings that I have had since we first learned that Jenna was pregnant!" he wrote. "I have waited my entire life for this moment and couldn’t have found a better person to build a family with. The past year and a half has brought so many things into my life that have filled me with the deepest of gratitude.
"A partner who radiates love, warmth, and kindness. A partner who has faced some of the hardest moments life can deal you with grace, humility, and a desire to learn from the ups and downs. A partner who is continuously growing from those lessons and who supports my growth as a person with love, unwavering support, and understanding."
"Jenna also brought with her one of the greatest gifts one could ever imagine...her beautiful daughter," he continued. "Evie burst into my life like a supernova and has continued to burn so brightly in it. I have learned so much about parenting already from watching how amazing Jenna is with her and Evie has taught me so much about what it means to love and communicate with a child and I can’t wait to give her a sibling and make our little family a little bit bigger."
The couple also expressed their excitement in an interview with PEOPLE, confirming the Step Up's daughter was over the moon when she discovered she was going to be a big sister.
"She is going around lifting up my shirt to literally anyone, and goes, ‘I’m going to be a big sister! Did you know there’s a baby in my mommy’s belly? Do you want to touch it?’" the actress turned best selling author said.
"I always said that I would love to expand my family. I was so excited by the option to do that and excited by that. And so the second I knew, I was thrilled with it,” she added.
Ahead of their bub's birth, Steve also told Us Weekly: "I’m nervous as can be, but I’m trying to just be calm about it and know that we’ve been doing this for billions of years, millions of years at least, so we’re going to be okay.
"There’s no way to even describe how excited you are at this moment, but we’re beyond. We’re very happy. It’s an incredible experience. I’m, like, every day just in awe of the fact that there’s a life growing inside of this human being that I love so much."