catherine schwarzenegger and chris pratt

Katherine Schwarzenegger Pratt and Chris Pratt

| Credit: Michael Buckner/Variety/Shutterstock

Katherine Schwarzenegger Pratt is marking her first Mother's Day as a mom!

The Gift of Forgiveness author, 31, welcomed daughter Lyla Maria with husband Chris Pratt last August. To celebrate the special day, the actor, 41, shared a loving tribute on social media Sunday.

"Happy Mother's Day to my sweet @katherineschwarzenegger This is your first year as a mom, your third year as a step mom, and 31st year as a hot momma," wrote Pratt, who is also a father to son Jack, 9, with ex Anna Faris."Thank you for everything you do for us. We love you!!" he added.Schwarzenegger Pratt also shared a sweet messagein honor of mom Maria Shriver. "Happy Mother's Day to the worlds greatest mother and happy first Mother's Day as a grandmama!" she wrote. "You've taught me everything i know about motherhood, about unconditional love, kindness, acceptance and you mother with such joy and ease."

"You are the greatest grand mama to Lyla Maria," she added. "She beams with JOY when she sees you, and today she's all yours! I hope to be half the mother you are. I love you deeply. ♥️"