However, she did not reply to any questions and instead headed into the venue.
Afterwards, she visited a luxury knitted lace company in Nottingham before concluding her day’s diary by taking part in a prizegiving ceremony at London’s Science Museum.
Her decision to not offer an update comes as Buckingham Palace was said to not be expected to offer continuous updates on how King Charles’s treatment is going.
The king told members of the Royal Family about his health news prior to going public. He spoke personally to both his sons Prince William, and Harry, about the diagnosis.
A Buckingham Palace statement issued on Monday said: “During The King’s recent hospital procedure for benign prostate enlargement, a separate issue of concern was noted. Subsequent diagnostic tests have identified a form of cancer.
“His Majesty has today commenced a schedule of regular treatments, during which time he has been advised by doctors to postpone public-facing duties. Throughout this period, His Majesty will continue to undertake State business and official paperwork as usual.
“The King is grateful to his medical team for their swift intervention, which was made possible thanks to his recent hospital procedure. He remains wholly positive about his treatment and looks forward to returning to full public duty as soon as possible.
“His Majesty has chosen to share his diagnosis to prevent speculation and in the hope it may assist public understanding for all those around the world who are affected by cancer.”
