What a moment! Christie Brinkley couldn’t help but praise her eldest child Alexa Ray Joel, as she watched her perform “Diamonds Are a Girl’s Best Friend.”

“Sunday Serenade from my stunning gem of a daughter,” the 65-year-old wrote via Instagram on Sunday, November 10. “@alexarayjoel performing for iconic jeweler @harrywinston. Hope wherever you are your day is sparkling with laughter!”

“Absolutely fabulous performance. You must be so proud. Thank you for sharing,” one person said in the comments section. Another added, “She is truly amazing!! Beautiful voice fits a beautiful girl!! She sings from her soul!!”

The legendary model shares Alexa, 33, with her ex-husband Billy Joel. The pair were married in 1985 before splitting in 1994. Christie also has two more kids. She welcomed son Jack, 24, with ex Richard Taubman, and daughter Sailor, 21, while married to Peter Cook.

Alexa Ray Joel Billy Joel
Amanda Schwab/Starpix/Shutterstock

Alexa is no stranger to performing — she’s considered singing with her famous father at her wedding. “My dad doesn’t know it yet, but we’re doing a duet,”  she exclusively told Closer Weekly at Smile Train’s 20th anniversary gala at Capitale NYC. “He’ll be cool with it. He’s very laid back, and he does whatever I want to do.” The young singer has also worked quite hard on her own career.

“I worked a long time to get good at what I’m doing,” Alexa explained. “Nobody handed me a recording contract because of who my father is.” However, she is thankful for her father and all he does.

“He has a way of making every song sound classic and iconic because it’s really very melody-driven,” she said. “That’s what I’m all about — old school.” Ever her sister Sailor is all about the potential duet!

Christie Brinkley Alexa Ray Joel Sailor

“I bet [Billy does perform],” the Dancing With the Stars alum told Life & Style. “I hope now that I’m older and can appreciate that, he plays at the wedding. It will be awesome!”

It is pretty certain that every member of this family is all about supporting one another through it all. We can’t wait what is in their future!