Maria Shriver's Daughter Katherine Schwarzenegger & Baby Lyla Twinned in Matching Outfits for the Little Girl's 1st B-Day

Nothing surpasses a mother's joy as she celebrates her children's milestones, and it was no different for Katherine Schwarzenegger as her daughter hit the one-year mark.

Katherine Schwarzenegger, 31, is celebrating her daughter Lyla's first birthday, and she cannot keep calm as she wore cute matching outfits with her now 1-year-old Lyla Maria.

Katherine posted the beautiful photo of the mother-daughter moment on the beach with the two facing away from the camera in pink gingham outfits.

She started the post by noting that she became a mother this time last year, adding that it has been a magical year watching the little girl grow from the infant stage to being a toddler.

She says she hung up birthday decorations the night before Lyla's birthday and got emotional thinking about how much of a blessing the little girl has been to her. She continued:

"Clearly, I have fully embraced the mommy and me matching moments, the girly outfits, the bows and the wonderful things my mom saved for me to pass on to her."

Lyla is Katherine's first child with her husband, Chris Pratt, 42. Pratt, however, is already a father to son Jack, whom he shares with Anna Faris.

Katherine and Pratt announced the arrival of their baby on Instagram in a post that showed the little girl's hand clutching her parents' fingers, accompanied by a caption that shed light on how excited they were.

Earlier in the month, Pratt had shared a photo of him and his wife on a hike, with Katherine looking heavily pregnant. Pratt captioned the photo with a hilarious message that said she was ready to pop yet couldn't stop.

[Arnold] jokingly admits that being someone's grandfather makes him feel old.

It may not be clear as to when exactly the couple met. For sure, though, Katherine's mother, Maria Shriver, was the matchmaker, and as a source revealed to People, she helped set the two up in 2018.

Pratt and Shriver were already acquaintances, which helped make it easier to set him up with her daughter. They would start talking consistently and go on multiple dates, including one with Katherine's dad, Arnold Schwarzenegger, and his girlfriend, Heather Milligan.

In the months that would follow, Pratt was often seen in the company of Katherine's family and started hitting the gym with Arnold in a bid to win over his father-in-law.

Katherine and Pratt got engaged in January 2019 and shared the good news on an Instagram post that showed off the beautiful engagement ring alongside a caption that read:

"Sweet Katherine, so happy you said yes! I’m thrilled to be marrying you. Proud to live boldly in faith with you. Here we go!

The two are reported to have wed in June of 2019 in Montecito, California, in a beautiful and intimate ceremony with only close friends and family in attendance.

And now the two are parents to a new baby girl. The news was received with lots of joy by first-time grandmother Shriver, 65. The NBC News anchor says she is delighted to watch her daughter grow into her role as a mother.

She also adds that her new relationship with her granddaughter has brought her immense joy, and she is grateful that she holds the title of grandmother.

Arnold also expressed his joy at having a granddaughter, saying that it was a beautiful feeling and adding that he was proud of Katherine and her husband for being wonderful parents to Lyla.

He praises the new parents for doing a wonderful job with Lyla, even though he jokingly admits that being someone's grandfather makes him feel old.