The sister of The Big Bang Theory actress Kaley Cuoco has admitted she's "so excited" about the star's big engagement news and insists she "couldn't have picked a better man."

27-year-old Kaley surprised fans by [uuid=18c92ffd-a045-4d1a-aa18-61744a793d30]announcing she was engaged to tennis player Ryan Sweeting[/uuid] after just three months of dating, but her younger sibling Briana has revealed she's "thrilled" for the happy couple.

Briana told E! News yesterday (October 7): "I am so excited. I love Ryan, I love Kaley. I couldn't have picked a better man for her and I'm thrilled."

The 24-year-old, [uuid=71c5e6af-939f-49c6-a93f-d1e699111ebf]who is currently competing on[/uuid] The Voice USA, said of her soon-to-be brother-in-law: "He only calls me 'sister' now, it's really cute. I love it. He's great, I'm really excited."

In the same interview, Briana also gushed over how supportive her famous older sister has been during her time on the TV talent show, calling Kaley her "rock."

Briana explained: "My sister and my parents, we all have just forever and ever wanted to be rocks and supports for each other."

She added: "Kaley is that for me and I am that for her, and it was incredible having her there at truly one of the best moments of my life."