The Princess of Wales is spending her fourth day in hospital after receiving a visit from her husband the Prince of Wales.

William kept Kate company at her bedside in the London Clinic during a low key, private trip to see his wife on Thursday.

The future Queen was admitted to the private hospital on Tuesday for successful abdominal surgery, which Kensington Palace said was planned.

The Prince of Wales drives away from the London Clinic after visiting the princessThe Prince of Wales drives away from the London Clinic after visiting the princess (Lucy North/PA)

She is said to be “doing well” but will remain in the exclusive clinic for between 10 to 14 days, and is not expected to return to official duties until after Easter.

Kensington Palace announced the news on Wednesday, with Buckingham Palace triggering a double royal health scare when 90 minutes later it revealed the King was to be treated in hospital for an enlarged prostate.

Heir to the throne William has stepped back from official duties for several weeks to juggle looking after their children Prince George, Princess Charlotte and Prince Louis and care for his wife.

The Prince and Princess of Wales with Prince George, Princess Charlotte and Prince LouisThe Prince and Princess of Wales with Prince George, Princess Charlotte and Prince Louis (Chris Jackson/PA)

The family live in Adelaide Cottage in Windsor’s Home Park and will be being supported by their staff, including loyal, long-standing nanny Maria Teresa Turrion Borrallo.

Kate’s family Carole and Michael Middleton and siblings Pippa Matthews and James Middleton are also expected to be hands-on in helping the Waleses navigate the next few months as the princess recovers.

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The family of inspirational child fundraiser Tony Hudgell is among those who have sent get well messages to the princess, as they urged her not to try to be “superwoman” and rush back to work too soon.

The Princess of Wales with Tony HudgellThe Princess of Wales with Tony Hudgell during a visit to officially open the Evelina London Children’s Day Surgery Unit in December (Ian Vogler/PA)

Nine-year-old double amputee Tony, who has raised more than £1.8 million for charity, counts Kate as his “number one supporter”.

Tony’s mother Paula Hudgell said: “She is very special to us. She has been absolutely wonderful and has been a number one supporter through Tony’s fundraising and everything with the hospital.”

She added: “Get well soon, but take your time. We all try to think we are superwoman, especially when we have got children.

The Princess of Wales taking part in a Dad Walk during a visit to the Dadvengers community group in Arnos Grove, north LondonThe Princess of Wales taking part in a Dad Walk during a visit to the Dadvengers community group in Arnos Grove, north London in November (Yui Mok/PA)

“She needs to take her time and not rush back to things. Take each day as it comes.”

With the King due in hospital next week for corrective treatment for his benign condition and William – the next in line to the throne – and Kate out of action for the immediate future, Charles’s slimmed down monarchy – with three of the most senior royals missing – has been put under pressure in a way not seen before during his reign.

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Joe Little, of Majesty magazine, said the health troubles have compounded the problem facing the small band of working royals.

The King, Queen and the Waleses during the Trooping the Colour celebrationsThe King, Queen and the Waleses during the Trooping the Colour celebrations (Victoria Jones/PA)

Mr Little said: “The working members of the royal family have been under pressure to maintain the level of engagements undertaken by a much larger team in years gone by.

“Suddenly removing three of the most senior players because of health issues compounds the problem considerably, but at least the King will be out of action for only a relatively short period.”

The Queen is still carrying out engagements, joining the Princess Royal, the Duke and Duchess of Edinburgh, the Duke and Duchess of Gloucester, the Duke of Kent and Princess Alexandra as the current working monarchy – with the latter two appearing increasingly frail in recent years.

All are in their 70s and 80s except for Edward, who is 60 in March, and Sophie, who celebrates her 59th birthday on Saturday.

The Duke of Sussex, whose controversial accusations have left the royals reeling, and the disgraced Duke of York remain in the line of succession but both have stepped down as working royals.

Camilla insisted on Thursday, however, that the King was “fine” and “looking forward to getting back to work”.

Queen Camilla opens the new ‘Safe Space’ during a visit to Aberdeen Art GalleryQueen Camilla opens the new ‘Safe Space’ during a visit to Aberdeen Art Gallery (Andrew Milligan/PA)

Charles – a known workaholic – often stays late at his desk dealing with his correspondence and official papers into the early hours, but he has generally enjoyed good health, and keeps fit by walking and gardening.

He has postponed a number of engagements and will have been ordered by his doctors to take it easy.

The 75-year-old monarch – who held the record for being the nation’s longest serving heir apparent – acceded to the throne just 16 months ago on the death of his mother Queen Elizabeth II, who was the head of state for 70 years.