Trooping the Colour has marked the sovereign's birthday with a ceremonial parade for the last 260 years

Credit: JEFF MOORE/PA

She has postponed all Royal duties to focus on her recovery since then and has not made an official public appearance since the family’s walk to church at Sandringham on Christmas morning.

However,Kensington Palace has not yet confirmed or denied that the Princess may make a short appearance at Saturday’s event alongside the rest of her family.

In the last official update from the palace on March 22,it was said that she would only return to those duties when she is “cleared to do so by her medical team”.

Despite this,a source explained at the time that the Princess “may be keen to attend events as and when she feels able to,in line with medical advice”. They added that “any initial public events will not necessarily signal a return to a regular public schedule.”

A short appearance on the Palace balcony at the Trooping ceremony may be considered the right kind of high-profile,low-pressure event to join in an unofficial capacity,providing the Princess feels well enough to do so.

The Princess of Wales's last public was during her family's walk to church at Sandringham on Christmas morning

Credit: SAMIR HUSSEIN/WIREIMAGE

Trooping is not an event that the Palace provides a running commentary on regarding which members of the family will be in attendance,so it may be left to the day to find out.

The Princess’s attendance would come after she missed the Trooping rehearsal,the Colonel’s Review,last Saturday,at which she was set to play a starring role for the first time as the Colonel of the Irish Guards.

Instead,she wrote to the regiment,wishing troops the best of luck and saying she was sorry that she could not attend while continuing her recovery from cancer.

Writing as Colonel Catherine,she said: “I wanted to write and let you know how proud I am of the entire regiment ahead of the Colonel’s Review and Trooping the Colour. I appreciate everyone trooping this year has been practising for months,and dedicating many hours to ensuring their uniforms and drill are immaculate.

“Being your Colonel remains a great honour,and I am very sorry that I’m unable to take the salute at this year’s Colonel’s Review. Please pass my apologies to the whole regiment,however I do hope that I am able to represent you all once again very soon.”

Signing off with the Irish Guards motto of “Who will separate us?” she added: “Please send my very best wishes and good luck to all involved. Quis separabit.”

An appearance at Trooping this weekend,however,would mean shared attention on all members of the family in attendance,including the King as he partakes in an ever-so-slightly amended birthday parade.

The monarch will take part in Saturday’s parade but will inspect the soldiers from a carriage rather than on horseback as he continues his own cancer treatment.

Charles,75,has only recently returned to public-facing duties while still receiving treatment and is therefore adapting his programme of work in line with medical advice so as not to take any undue risks to his health.

Despite this,the workaholic monarch will be delighted to be able to partake in the jubilant event,even if the Royal balcony snapshot might look a little different this year.