"The couple is so excited for their new addition and have been showered with love from their family and friends," a source told ET. "Chris was there for the the birth and the couple can’t stop taking their eyes off their daughter. Katherine and Chris are doing well and Katherine is enjoying the experience of being a first time mother."
“Giving birth was such a special moment for Katherine. She was overcome with emotions when she first held her daughter and was so thankful to have Chris there," the source added. "Everything is new for Katherine and she’s glad Chris is there to help her through everything.”
Katherine's brother, Patrick Schwarzenegger, also confirmed the news in an exclusive video obtained by ET on Sunday.
"They're doing great -- just got her a little gift," Patrick said, while leaving a market in Santa Barbara, California, on Sunday. The 26-year-old gave a thumbs up when congratulated on becoming an uncle. He then showed the camera a package with a pink ribbon, before getting into his car.
While Patrick did not mention when the baby arrived, a source tells ET that Chris' car was spotted at St. John’s Hospital in Santa Monica, California, on Friday afternoon. ET has reached out to reps for the couple for comment.
Katherine's father, Arnold Schwarzenegger, mother, Maria Shriver, and siblings, Christina and Christopher, were snapped visiting her house. The clan later left with Arnold smoking a cigar as he headed to the car.
Later in the morning, Maria and others were seen paying the new mom another visit. Arnold meanwhile headed out for a bike ride, during which he bumped into Patrick and Christina at Caffe Luxxe.
A delivery van was seen dropping off flowers to Chris and Katherine's home on Saturday.
"Chris and Katherine are extremely happy to be pregnant with their first child," the source said. "The couple knew going into their relationship that having kids together was important to them, so when they found out the news, they were extremely happy. Although Katherine was busy promoting her book in the beginning of her pregnancy, she now has time to be at home and get things ready for when the new addition arrives. Chris is so excited."
“Chris and Katherine have had an incredible first year of marriage," the source said. "The couple plans to celebrate their first wedding anniversary with something small as their baby is set to arrive soon."
"Chris and Katherine are thankful for their alone time recently as it has allowed them to enjoy the pregnancy together, giving them a forced sense of time to relax and prepare," the source added about how they've been doing amid the coronavirus pandemic. "They know their baby is coming soon and can't wait to welcome their new addition."
Clearly, Katherine's famous family is also incredibly excited about the couple's first baby together. Her father, Arnold, appeared on The Tonight Show Starring Jimmy Fallon in May and talked about the exciting news.
"Think about this for a second... there's three gene pools that you can do," he pointed out. "There's Kennedy, there's Schwarzenegger, and Pratt. We can do anything. We can go and solve the Cuban missile crisis... We can go and train dinosaurs. I mean, think about it!"