A medical expert has reminded divorced partners it is perfectly normal to undergo a 12-month grieving process, after Karl Stefanovic’s ex-wife Cassandra Thorburn spoke publicly and bravely of the anguish of her separation.

Speaking for the first time since the marriage fell apart 15 months ago, Ms Thorburn, 46, told Woman’s Day on Monday the divorce felt like a death in the family, and that she struggled to get out of bed in the morning.

“I realised I was going through stages of grief, and to me it was like someone had died.”

The former journalist said she felt “completely gazumped” when she “realised Karl had gone” after 21 years of marriage.

“There were days in the beginning I would get up, put on a brave face and drop the kids at school, then I’d get to the back door and I would lie in a heap for the rest of the day, unable to move – there were very dark days.

“I slept on the couch in front of the fire for months because I didn’t want to go near the marital bed. I was in a very dark place.”

That kind of grief is a “very normal response” for both exes after a divorce, said Adjunct Associate Professor Amanda Gordon, from Sydney’s Armchair Psychology Practice.

“We find that even people who are the ones that choose to leave, and sometimes leave a bad relationship, they can feel immense grief and loss – because any ending is an ending,” Dr Gordon The New Daily.

“We have to grieve it before we can move forward.”

Ms Thorburn told the magazine she was focussing on being the best single mum she could be to their three children – Jackson, 18, Ava, 12, and River, 10.

“I get up every day with only one purpose – to make sure my three beautiful kids are happy – everything else really doesn’t matter.”

“I get up every day with only one purpose – to make sure my three beautiful kids are happy – everything else really doesn’t matter,” Ms Thorburn said. Photo: Getty

Dr Gordon said the person left behind sometimes felt shock before they could grieve.

“Sometimes they don’t know it’s going to happen until it happens. So the shock is the thing they’re responding to in the first instance,” she said.

“I think for a significant number of people who are left in the lurch whose partner leaves them in the marriage, there’s an element of shock, grief and abandonment. There can be some fury, there can be some anger.”

Dr Gordon said 12 months was a typical grieving period after a marriage breakdown.

“She’s been through Christmas, his birthday, her birthday, the kids’ birthdays, school holidays. She’s done all these things. Next time around, the birthday isn’t quite so hard,” she said.

“I would expect about 12 months to go by for it to be time to start reflecting: ‘What do I want to be different? What have I learnt from this?’

“Sometimes it’s going to be, ‘I want to get back at him’, or a change in career, or ‘focus on my kids’. There’s a whole range of responses that people can have.”

Dr Gordon also said it was important to keep denigrating comments out of the public eye and off social media, and instead confide in a close friend.

“Most parents after the initial shock understand their behaviours can impact their children,” she said.

“Even 10-year-old’s are across everything, so there’s no keeping things private in the way things used to be two decades ago. Everyone can see everything.

“There is no doubt that it’s not good for the kids to have parents publicly or privately denigrating each other.”

Stefanovic reportedly met his new girlfriend Jasmine Yarbrough, 33, at the end of 2016. He gushed over her in an interview last week with News Corp.