Camilla, Duchess of Cornwall, will likely step up to the plate and carry out duties for Queen Elizabeth II if the monarch is unable to continue with her public engagements.

Palace aides are said to be thinking of calling on members of the Counsellors of State to work on behalf of the British monarch as she continues with her medical leave. These counsellors include the two royals next in line to the throne, Princes Charles and William, and also Princes Harry and Andrew.

However, the Prince of Wales and the Duke of Cambridge are said to be out of the picture because of their busy schedules. That leaves the Duke of Sussex and Duke of York, who are both no longer working for the Royal Family.

"A Counsellor not domiciled in the UK cannot act, so that excludes Harry. The next in line and over the required age of 21 would be Princess Beatrice. However, most of the functions of the Head of State can be devolved," Vernon Bogdanor, author of "Monarchy And The Constitution," told the Daily Mail adding, "It is not, for example, constitutionally necessary for the Queen to attend the State Opening of Parliament."

Meanwhile, Dr. Craig Prescott, a constitutional expert at Bangor University, said the absence of Counsellors of State "could impede the operation of the constitution. It could certainly make the day-to-day running of Government much more tricky."

He said Queen Elizabeth II "may look to add the Duchess of Cornwall, who would become a Counsellor of State when Charles is King anyway. Or they could go down the line to Princesses Beatrice or Eugenie, or add more members of the family, like Princess Anne or Prince Edward to the list."

A palace source called it a "constitutional headache" and revealed that there are concerns about who will take over Queen Elizabeth II's duties with members of the Counsellors of State not available to do so. In the meantime though, Buckingham Palace has reassured the public that Her Majesty is feeling well and is doing light duties from her desk. Prime Minister Boris Johnson also said she was in "good form" when they spoke last week.

Prince Charles and Camilla, Duchess of Cornwall
Prince Charles and Camilla, Duchess of Cornwall Chris Jackson/Getty Images