However, the image created even more social media speculation when eagle-eyed fans spotted that the sleeve of Charlotte’s arm didn’t line up.

The picture, part of the family’s annual tradition of posting a message for Mother’s Day, was supposed to go some way to answering growing questions from the public about the princess’ wellbeing.

It was accompanied by a Mother’s Day message along with a “thank you” from the princess for the public’s “continued support” while she recovers following 13 nights at the London Clinic, in central London, after the surgery earlier this year.

“Thank you for your kind wishes and continued support over the last two months,” the post read. “Wishing everyone a Happy Mother’s Day.” It was signed “C” for Catherine.

In January, the palace announced that Catherine had been admitted to hospital for planned abdominal surgery.

While the precise nature of her condition was unknown, there was a plea for privacy and guidance that she would not return to public duties before Easter. The palace has said the condition is not cancer-related.

With so few details about her condition released since, the question of “Where is Kate?” has increased on social media, accompanied by increasingly outlandish conspiracy theories.

Enacting their “never complain, never explain” strategy, what started as Facebook and TikTok chatter about her “disappearance” from public life flipped over into the mainstream media amid an information vacuum over her illness, the nature of King Charles’ cancer and then a “personal matter” that kept William away from a memorial for his Greek godfather, the late King Constantine II, last month.

In the mainstream media in recent days, the BBC has referred to the situation as “a royal dilemma”, the New York Times wrote about the “feverish speculation” over Catherine’s condition and the LA Times appeared to go one better with a piece about the frenzy over her “disappearance”.

In Europe, Spain’s El Pais ran a headline that read: “Scant information on the health of Charles III and Kate Middleton, who was seen in a photograph Monday, raises more questions than answers.” In tabloid magazines in Germany, conjecture ranged from Kate being the victim of a domestic abuse attack to being pregnant with twins.

The palace, meanwhile, reiterated it would provide updates on her recovery when there was significant new information to share.

It has said Catherine wants her personal medical information to remain private and that it would only provide updates on her progress when there was significant new information to share.

The Times reported this weekend that the palace had appealed to journalists for calm amid what they have noted is a rising sense of panic about the princess’ condition.

“The guidance hasn’t changed,” a palace source told the paper. “We made it clear that the princess would be unlikely to return before Easter and that’s what’s happening.”

Catherine’s surgery came on the same day that palace officials said Charles, 75, would also be entering hospital for treatment for an enlarged prostate.

During the King’s hospital stay, his medical team discovered he had an unspecified form of cancer. The monarch has had to postpone his public engagements while he undergoes treatment, although he has been pictured carrying out some of his duties as head of state.

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Buckingham Palace also marked Mother’s Day, posting a picture of Charles kissing the hand of his late mother Queen Elizabeth, who died aged 96 in September 2022.

“Wishing all mothers, and those who are missing their mums today, a peaceful Mothering Sunday,” the accompanying message said.

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