Pratt created an adorable collage on Instagram with some candid moments in honor of Schwarzenegger turning 31. "Happy Birthday Sweetie!" the Jurassic World actor wrote. "You have brought so much light into my life. I’m so glad to be home with you and Lyla. You’re a great mom, a great step-mom, a great wife, daughter, sister and friend. The world is brighter with you in it. I am one lucky man. Thank you for the love, support and partnership. I love you."
In one snap, a beaming Schwarzenegger held their baby close, but her face is covered by a Santa Claus emoji. Other photos in the collage show Schwarzenegger while she was pregnant as she cradled her baby bump, as well as shots of the couple together.
"Awww I love you," Schwarzenegger replied in the comments.
Several fans thought the Santa cover-up was hilarious. "Your baby looks a lot like Santa Claus," a user noted. "I never realized how much Lyla looks like Santa Claus ... it’s uncanny," one fan joked. "Omfg she gave birth to Santa?! Holy lucky," another added.
Pratt and Schwarzenegger tied the knot in June 2019 and welcomed Lyla in August. Pratt also has a son, Jack, whom he shares with his ex-wife, Anna Faris.
Pratt confirmed the arrival of his daughter on August 10 with an adorable photo of his wife holding his baby’s hand. "We are beyond thrilled to announce the birth of our daughter, Lyla Maria Schwarzenegger Pratt. We couldn’t be happier. Both mom and baby are doing great. We are extremely blessed. Love Katherine and Chris," he wrote at the time but has been keeping his family life private ever since.
A source told Us Weekly in August that Schwarzenegger loves being a mom. “She’s in baby bliss and so grateful to be a mother — something she always wanted to be," the insider shared. "They feel blessed to spend this time together and be a new family. Chris says Katherine is a natural and she hasn’t missed a beat since they brought their baby girl home!"
"After they got married, they couldn’t wait to grow their family," a source previously told PEOPLE. "Jack will be a great big brother. Katherine always says that he is the sweetest, most caring boy. Katherine thinks Chris is an amazing dad. She allowed herself to fall in love with Chris quickly because she early on realized that he is a great family guy."
The source also explained that Schwarzenegger is "going through all the first-time mom emotions."
"She is extremely happy, but a bit tired and overwhelmed. Chris keeps being amazing though. It’s comforting for Kat that he is already a dad and understands how it is to have a newborn," the source said.