Kate and William are 'shaken and devastated at speculation about their marriage and intend to release new photo to mark Prince Louis' birthday next month' - as friends reveal Princess of Wales could also use public engagement to open up about health issues

William and Kate are said to be 'shaken and devastated' at the speculation about their marriage on social media and could address the Princess of Wales' health condition at public engagements next month, her close friends have said.

Princess Kate has not made an official public appearance since she underwent major abdominal surgery on January 16, leading to a growing tsunami of speculation over her unknown health condition.

Speculation only intensified when she publicly took the blame for the family photograph released by Kensington Palace on Mother's Day, which was 'killed' by six of the world's top picture agencies over concern that it had been 'manipulated'.

As well as a number of imperfections in the photoshopped image, viewers also spotted that Kate appeared to not be wearing her wedding ring, which sparked multiple unfounded theories online about the state of her marriage. 

Despite this tumultuous few weeks for the Royal Family, it is expected that they will still uphold the tradition of releasing a new photograph to mark their children's birthdays, the next being Prince Louis on April 23.

They may use it as an opportunity to speak about her health, it has been reported.

'They are at their most open when out interacting with members of the public and I can see a world in which the princess might discuss her recovery out on engagements,' a source told the Sunday Times.

'If she was going to do it, that's how she would do it.'

Kensington Palace released the picture of the Princess of Wales since surgery

Kate posted the apology on the Prince and Princess of Wales' Instagram account 

'They appreciate the public's love and affection for their children and know there is a public appetite to see them on their birthdays,' an aide added.

Although it is understood that no 'firm decision' has been taken, the couple has been shaken after the online hysteria around Kate's health.

The Sunday Times quoted a friend as saying: 'They will want to be clear and more open, but they'll do it when they feel ready. I would expect that to be her instinct and it will be her call. They're not going to be rushed.'

A source close to Kate claimed all she intended to do was 'bring a bit of joy' and release a reassuring image to thank the public for their ongoing support.

The Princess is not expected to return to frontline duties until after April 17, when her three children go back to Lambrook School, near Ascot after the Easter holidays.  

Another friend insisted that it was just someone trying to project the polished image that the public has come to expect: 'It's a photo that she knew everyone would pore over so she pored over it herself — she likes trying to make the family look the best they can.'

Earlier this week, Kate made the unexpected decision to publicly take responsibility of the mishap and issue a personal apology on Instagram: 'Like many amateur photographers, I do occasionally experiment with editing,' she wrote.

A friend and adviser to the couple said that Kate's only mistake was not telling her team that she had edited the photos.

'But she came out and said sorry. The photo was a misstep, even with something as innocent as that you should disclose altering it.'

Prince and Princess of Wales with their three children Prince George, Princess Charlotte and Prince Louis in Norfolk

William and Kate were spotted leaving Windsor for Westminster Abbey to attend The Commonwealth Day Service

Now sources within the royal circles are warning of the negative affect rumours may be having on the future Queen as she recovers from her major surgery in January.

One insider said: 'I worry about all this attention on Catherine. She did not look happy at all in the car on Monday.'

Kate was seen in the backseat of a car with her husband as he left Windsor to travel to London for two public engagements.

The Mail understands she was on route for a 'private appointment' and she did not accompany William publicly.

Despite calls for the original image to be published, Kensington Palace insisted it would not be reissuing the unedited photograph of Kate and her children.

It comes after further details emerged about the photo shoot, with William having taken the picture in just a 40-minute window on Friday before the Princess edited it twice in Photoshop to 'make it the best it can be'.

The Prince of Wales took the picture of his smiling family on a £2,900 Canon camera before Kate made edits to improve the photo ahead of its public release on Instagram on Sunday.

Royal commentator Jennie Bond suggested Kate 'must feel under intense pressure now whenever she's going to be seen in public' after her major surgery in January.

Also rallying round Kate today was royal expert Angela Levin who praised her for being 'honourable'.