Karl Stefanovic’s ex-wife Cassandra Thorburn is every inch the proud mother as she shares sweet snaps of their youngest son River, 17, attending his school formal

Cassandra Thorburn was every bit the proud mother as she gushed over her son River as he attended his prom.

The 53-year-old author shared on Instagram on Friday a gallery of adorable snaps of himself and Karl Stefanovic’s youngest son River, 17, as they attend his high school’s prom.

River looked very stylish in a navy blue suit and beamed from ear to ear as he posed with his date Daisy Thomas, a competitive skier.

Wearing a blue satin dress, Daisy was photographed attaching a corsage to River’s lapel as they got dressed for the exciting night.

For once, Cassandra looked very proud of her son, as she wrapped her arms around him with a big smile.

Cassandra raved about her son in the caption, admitting that the night had “melted” her heart.

‘Year 12 formal… @daisyy.thomas @riv_sz you both look amazing and let me take all the photos I wanted! Have a lovely night! #mummymoments,’ she wrote.

“My heart melts for this young man,” she added on Facebook. “I wouldn’t miss these moments for anything.”

The author (pictured), 53, shared a gallery of adorable snaps of her and Karl Stefanovic’s youngest son River, 17, on his way to his high school graduation on Instagram on Friday

Karl and Cassandra went their separate ways in 2016 after 21 years of marriage, and Cassandra has since disappeared from the spotlight.

She now works in sales and support for Sydney’s aged care sector and previously spoke of how happy she was to be able to put a life ‘behind’ her in the spotlight.

In addition to River, the exes also share son Jackson, 24, and daughter Ava, 19, who now goes by her middle name Willow.

Jackson is passionate about music and previously shared how an acoustic guitar he received from his father Karl for his 17th birthday helped him with his mental health.

River looked very smart in a navy suit as he beamed from ear to ear while posing with his date Daisy Thomas, a competitive skier

Daisy wore a blue satin dress and was photographed fastening a boutonniere into River’s lapel as they got dressed for the exciting evening

River was also seen giving Daisy a matching white corsage as they joined their classmates getting ready for the formal part.

‘I have struggled with ADHD and various other mental health issues my entire life. Sometimes I found it really hard to find my place in the world,” he told Woman’s Day in 2022.

“But my passion for music and singing has helped me through some pretty tough times.”

‘My parents are still my biggest fans. Family is everything. Thanks to their unconditional love, music and song, my journey through life suddenly became a lot lighter,” he added.

Cassandra and Karl (both pictured) split in 2016 after 21 years of marriage, and Cassandra has since stepped away from the spotlight

In addition to River, the exes have a son, Jackson (pictured with Karl), 24, and a daughter, Ava, 19, who now goes by her middle name Willow.

Meanwhile, Willow is currently studying fashion at the London College of Fashion, which is part of the University of the Arts London – a collection of six of the most prestigious art schools in the world.

The company recruits globally and its alumni list is a Who’s Who of the creative industries, from illustrator Quentin Blake to Florence Welch of Florence and The Machine.

Willow is also ready to follow in her famous father’s footsteps and start a career in the spotlight. She signs with Precision MGMT to start a career in modeling.

She has the full support of her parents Karl and Cassandra Thorburn in starting her modeling career.

Willow is also ready to follow in her famous father’s footsteps by launching a career in the spotlight, signing with Precision MGMT to launch a career as a model

Karl is also father to another daughter Harper, four, who he shares with his second wife, shoe designer Jasmine Yarbrough (all pictured with Willow)

“She doesn’t go into anything blindly, especially in the fashion world. She’s a strong, independent young woman and wants to pursue many things in life. We love her spirit,” Karl, 49, told Stellar magazine in 2021.

Cassandra added: “I encourage all my children to work hard and pursue their dreams and aspirations. Willow knows who she is and what she wants, and those qualities make me very proud.”

Karl is also father to another daughter Harper, four, who he shares with his second wife, shoe designer Jasmine Yarbrough.

The Nine presenter found love with shoe designer Jasmine in late 2016 after splitting from Cassandra, and the couple married two years later in December 2018.