A Baby Girl! Chris Pratt and Katherine Schwarzenegger Welcome Their First Child

Chris Pratt and Katherine Schwarzenegger Introduce Daughter Lyla Maria: 'Couldn't Be Happier'

"We are beyond thrilled to announce the birth of our daughter," Chris and Katherine Schwarzenegger Pratt announced on Monday

Katherine Schwarzenegger Pratt is a mom!

The author, 30, and her husband, Chris Pratt, have welcomed their first child together, multiple sources confirm to PEOPLE.

Schwarzenegger Pratt's brother, Patrick, also confirmed the news in a video shared by Entertainment Tonight on Sunday, saying that his sister and brother-in-law were "doing great."

"Just got her a little gift," he added while flashing a glimpse of a little box wrapped with a pink bow.

A source close to the couple further confirmed that the new mom is "doing well" and spent the weekend at home with her husband and baby girl.

"They knew they were having a girl and were thrilled about it. Kat had a good pregnancy and she is hoping for a quick recovery. So far, so good," the source told PEOPLE. "She 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."

Steve Granitz/WireImage Katherine Schwarzenegger Pratt and Chris Pratt

The source continued on to say that due to COVID-19 restrictions, the "families couldn't meet the baby at the hospital."

"As soon as Kat and the baby got home from the hospital, Maria and Arnold visited. They are both proud grandparents of course. They also visited over the weekend. Maria is making sure that Kat has everything she needs," the source added.

Reps for the couple have yet to comment.

The newborn joins her big brother Jack, who turns 8 on Aug. 17. Pratt, 41, shares his son with ex-wife Anna Faris.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Ari Perilstein/Getty Chris Pratt and son Jack in February 2018

Katherine Schwarzenegger Pratt and Chris Pratt

RELATED: Chris Pratt Says Pregnant Wife Katherine Schwarzenegger Is "Ready to Pop" as They Enjoy Hiking Date

In April, a source told PEOPLE that Pratt and Schwarzenegger Pratt, who wed in June of last year, are excited for Jack to become a big brother. "After they got married, they couldn't wait to grow their family," the source said.

"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 insider shared. "She loves being an extra mom to Jack."

A friend also added, "They can't wait for Jack to have a sibling."

Schwarzenegger Pratt opened up about being pregnant amid the ongoing coronavirus pandemic in an Instagram Live chat with Dr. Zelana Montminy in June, saying Pratt has been "very understanding" during this time.

Mega Agency Chris and Katherine Schwarenegger Pratt

RELATED VIDEO: Chris Pratt Has Been a "Dream Husband" Doting on Pregnant Katherine Schwarzenegger: Sources

Chris Pratt Has Been a 'Dream Husband' Doting on Pregnant Katherine Schwarzenegger: Sources

PLUS: Lea Michele is expecting her first child with husband Zandy Reich

"I'm really lucky to be living in very close proximity to my family, which has been very helpful," The Gift of Forgiveness author said, adding that Pratt was a "very wonderful husband."

"It's been amazing having him home and also very understanding about my need to sanitize everything, having everyone wear masks all the time," Schwarzenegger Pratt said. "That's been helpful."

In May, Pratt spoke about how he's been holding up during the pandemic, joking to Extra that he has "gained a little weight" while social distancing with his pregnant wife.

"Pickles and ice cream. I never thought I would like 'em so much," he mused.

RoundPondEstate/Instagram Katherine Schwarzenegger Pratt and Chris Pratt

RELATED: Arnold Schwarzenegger Jokes About Powerful "Gene Pool" Behind Daughter Katherine's Baby on the Way

The Guardians of the Galaxy actor went on to discuss how he has been handling the pregnancy, candidly telling host Billy Bush, "Can I be honest with you? I found myself complaining the other day about a little bit of low back and hip pain and how I've gained a little weight in quarantine … and she just looked at me sweetly."

He quipped, "I was like … 'Oh, right, right, I don't really get to complain about that to you right now, do I?' "

A source previously told PEOPLE that Pratt has been nothing short of a "dream husband" to the Rock What You've Got writer throughout her pregnancy.

"Katherine is doing well, and Chris has been taking care of her," the insider said. "Katherine still calls him her dream husband. They are very happy together."

"Chris has been doting on Katherine, and the pregnancy has brought them even closer," a friend of the couple added.