Michael Buckner/Variety/Shutterstock Katherine Schwarzenegger Pratt and Chris Pratt
"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 message in 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. ♥️"
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Schwarzenegger Pratt recently opened up about having an amazing partner in Pratt.
In the latest episode of her Instagram Live series, "BDA (Before, During & After) Baby," she chatted with her friend and new mom Iskra Lawrence about the difficulties moms have with body image and the idea of snapping back shortly after giving birth.
The author explained that Pratt has "always been super supportive" of her body and how a woman's body changes before and after birth.
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"He'll look at our daughter and be like, 'Can you believe your body is able to feed our baby?' " she said.
"Sometimes, I think — especially as women with this pressure to bounce back after baby — you have to keep in mind that when you're breastfeeding, you need to, as my husband says, 'eat to win,' and to feed yourself so you can also properly nourish your baby. Because for a lot of people, what you eat and how you treat your body also hugely impacts your milk supply," she added.
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Back in August, the couple shared the first photo of their newborn baby girl's hand alongside a sweet announcement about her birth shortly after she arrived.
"We are beyond thrilled to announce the birth of our daughter Lyla Maria Schwarzenegger Pratt," the caption on both parents' posts read at the time. "We couldn't be happier and we feel extremely blessed! Love, Katherine and Chris."