Kaley Cuoco, who is pregnant and expecting a baby girl with Tom Pelphrey, "couldn't be happier":

 In other words, Kaley Cuoco can't wait to become a mom.

A source close to Kaley Cuoco tells PEOPLE in this week's issue that she is "extremely eager to be a parent" and "couldn't be happier" with Ozark star Tom Pelphrey, with whom she is expecting her first child, a daughter.

"She is really pleased that it is happening," the source continues. "Kaley has had this dream for quite some time. I've never seen her happier."

Another insider said, "Kaley will be a fantastic parent." The children love her because of her humour, warmth, and charisma.

Last week, the happy news spread that Cuoco, 40, and Pelphrey, both 40, are expecting their first child together. The actress revealed they are having a girl by posting several adorable images of herself and Pelphrey, including a few of the interior of a cake with pink icing.

Sign up for PEOPLE's free daily newsletter to receive the latest scoop on everything from breaking celebrity news to inspiring human interest stories delivered straight to your inbox.

She also displayed images of her growing belly, a variety of adorable baby onesie options, and a touching photo of her holding a positive pregnancy test as she and her partner gazed at each other tenderly.

"Beyond grateful and ecstatic: "Baby daughter Pelphrey due in 2023." I really appreciate you, @tommypelphrey!" Cuoco shared a message on Instagram.

The Banshee actor posted many of the same photographs on Pelphrey's profile with the captions, "Furthermore, it improved even further. I adore you, @kaleycuoco, even more than before."

They are "thrilled that she's found the one," a pal of the Big Bang Theory alum said of Cuoco and Pelphrey's romance.

"Tom is a wonderful person who accepts Kaley just as she is. They have a wonderful relationship because he treats her so well. What's more, their relationship exudes an air of quiet maturity "the insider chimes in.

Cuoco told Extra at the screening of her new film Meet Cute that she and Tom Pelphrey had "love at first sight" when they met at the April premiere of Ozark.

Cuoco remembered that their first real-life meet-cute occurred at the premiere of Ozark, when her manager had invited her as her guest. "In a way, it seemed as though angels had begun to sing. And I thought, "Hallelujah!" It had a magical quality; in fact, it was ideal."

A plaque on the Hollywood Fame Walk of Fame was the first public appearance the pair made together after they announced their romance in May. They sat hand in hand to celebrate Flight Attendant executive producer Greg Berlanti's achievement. After that, they took their romance on the red carpet of the 2022 Emmy Awards, where they were both nominees.