EXCLUSIVE: Kaley Cuoco on Having 'Baby Fever' and Why Her Girlfriends Are So Important

Kaley Cuoco is super supportive of her close-knit gal pals.

ET spoke with the 31-year-old Big Bang Theory star as she supported the launch of her good friend Haylie Duff's new children's collection -- Little Moon Society -- in Los Angeles, where she talked about getting baby fever of her own due to all the adorable clothing.

"Is it weird that I want to wear these clothes? Is that weird?" Cuoco joked to ET's Carly Steel. "In the largest size possible? It does give you a little bit of baby fever! Everyone is so cute, everyone looks so adorable, hard not to."

WATCH: Kaley Cuoco Smooches Boyfriend Karl Cook -- 'We Love Rainy Days'

"... Yeah, I've got dogs," she joked.

Cuoco said that she and Duff, as well as actress Marla Sokoloff, have been friends for over 15 years. Duff's friends certainly came out in full force at her big event, including Ashlee Simpson and Jamie-Lynn Sigler.

"Marla and I go way back," Cuoco said. "So, all these girls, it's kind of a big group of friends that have been together for a very long time."

"I think it's important, and I think it shows the relationships have grown through the years," she continued. "And kids, and shows, and whatever we're doing, we always make the time to see each other. You know, girlfriends are important."

ET also spoke with Duff, who said that the biggest inspiration for Little Moon Society is her and business partner Jessica Frank's own kids. Duff is a mom to her 1-year-old daughter, Ryan, with fiance Matt Rosenberg.

"For us to make something that they could wear that was made here in Los Angeles, that we knew they would love to live in," Duff said.

WATCH: Kaley Cuoco's Boyfriend Karl Cook Cuddles Up With Her Ex Johnny Galecki on 'Big Bang' Set

As for Cuoco's personal life, all certainly appears to be going smoothly with her boyfriend, Karl Cook. Watch the video below to see his sweet Instagram message to her last month.