Karl Stefanovic’s estranged wife Cassandra Thorburn has hit back at a female journalist who labelled her a prime example of why women should not give up their careers to raise children.

Thorburn, an ex-ABC journalist, separated from husband Stefanovic in September after 21 years – the split the focus of much media scrutiny.

Both Stefanovic and Thorburn, who share three children together, have remained relatively tight-lipped since the separation, until Thorburn last week penned a Facebook post congratulating herself for helping Stefanovic’s Today show topple Channel Seven rival Sunrise in the ratings.

“This took a huge toll on my family and I, and I’m congratulating myself today for all the effort that went into making that [the ratings] happen,” Thorburn wrote.

Today celebrates winning the ratings for the first time in a decade. Photo: Instagram

“The suggestions, the story ideas, the constant counselling of questions for years. I’m giving myself a pat on the back tonight.”

Reacting to the post, news.com.au columnist Angela Mollard wrote a piece with the headline ‘This is why women should never give up their jobs’, citing Thorburn as a “lesson to us all”.

But Thorburn has herself responded with a piece for Pop Sugar, calling Mollard’s piece “cruel” and arguing it was a “damn shame” that women were often each other’s “biggest critics”.

‘She was my suga mama’

Karl Stefanovic met Cassandra Thorburn, then an ABC journalist, in Rockhampton, Queensland in 1995.

According to the Today host, it was Thorburn’s teasing that had him hooked from the start.

“She told me I looked preppy,” he told The Age in 2014.

“She said, ‘I suppose that’s how you got your job in television, because of your pretty-boy looks’.”

Earlier this year, Stefanovic joked during a live cross from his former home in Rockhampton that Thorburn had been his “suga mama” when they first got together.

Stefanovic has praised Thorburn for her support and ideas. Photo: Getty

“She [Cass] lived on the hill and she caught lots of breezers, and she was also on double my money,” he said of his “princely” $32,000 wage as a cadet reporter.

But it was Thorburn’s eventual decision to become a stay-at-home mother that found her at the centre of a very personal news.com.au column since the pair announced their split last month.

“If you’ve gone to school and possibly university, and you’ve had a career before you married, then for the love of your own self-worth hang on to your paid work in any way you can,” wrote Mollard on Tuesday.

“It’s bloody hard to retain love, support and mutual respect when one person is paid for their efforts and the other isn’t.”

Mollard cited Stefanovic’s female colleagues Lisa Wilkinson and Georgie Gardner as examples of how to combine motherhood and working life.

‘When will judgments from other women stop?’

In her “open letter to working mums”, Thorburn argued it was her right to give up a career without judgment.

“Dear working mums, I’m aware you spend your days in a competitive environment … It’s never ending. I get it.

Thorburn said she sympathised with working mothers. Photo: AAP

“What I don’t get is why, in my experience, you also feel you’re in competition with us, the stay-at-home mums who made a different decision than you.

“We don’t lunch every day, if that’s what you think. We are busy, we stay informed, we fulfil the needs of our family.”

Referring to Mollard’s article, Thorburn said she had great respect for working mums, but wished their stay-at-home counterparts could be shown the same courtesy.

“Next time a working mum rolls her eyes at your stay-at-home status, hold your head high,” she wrote.