"Big Bang Theory" actress Kaley Cuoco has been shedding a lot of tears lately, but all for a good reason. 

Not only did the lovable, bubbly blond get engaged to tennis star Ryan Sweeting but her sister/best friend, Brianna Cuoco was a hit on Monday night's episode of "The Voice." 

Cuoco, 27, gushed about her recent engagement to Sweeting on Entertainment Tonight while she was on the set of her upcoming film, appropriated titled, "The Wedding Ringer." 

"[Sweeting] actually started a little fight with me and threw me off. I was like 'Oh my God, things aren't great.' He surprised me at the end of the night ... [when] he popped the ring out. It was amazing." Cuoco told ET. "From day one I just knew immediately and it's been magic. We have all the same family friends. We grew up with the same people, we just never met. So I kind of feel that I've known him my whole life. I know that it seems a little crazy on paper, but it's what works for us."

Cuoco will be sure to release any wedding jitters, if any, on the set of  the comedy, "The Wedding Ringer." The film also stars comedian Kevin Hart and actor Josh Gad. Hart's character offers best man services for socially awkward grooms who are in need of a best man. 

Now the spotlight is shifting towards Cuoco's 24-year-old sister, Briana, who also happens to be Cuoco's personal assistant -- and the CBS star couldn't be more thrilled.  

Briana stole the show on "The Voice" on Monday, where Cuoco and their family looked on in excitement.

During "The Voice's" blind audition, Briana sang a version of Lady Gaga's "You and I."

While she didn't start out that strong at first, she didn't let the nerves get the best of her. She belted it out and brought it home and was chosen by both "Voice" judges, Christina Aguilera and Cee Lo Green. Ultimately, Briana, inspired by "girl power," chose Aguilera to be her coach.

"This is what I want to do with my life," Briana said. "I don't want to make appointments, take the dogs for a walk, call the plumber ... I believe I'm meant to do this for the rest of my life and hopefully this will be the beginning of the journey," The New York Daily News reported.

Overwhelmed with emotion, Cuoco shared her thoughts on her sister's success.

"I've been waiting for something like this for so long for her," she told "The Voice" host Carson Daly. "She's deserved this her whole life. She's always put herself on the back burner for everyone else. This is her time now."