Kate, the Princess of Wales, gave strict instructions to Princess Charlotte, as they enjoyed Trooping the Colour, according to a lip reader.
The Princess of Wales briefly returned to public life to support the King and her husband, Prince William, at the celebrations for His Majesty’s official birthday.
The royal observed the proceedings from the balcony of the Duke of Wellington’s former office overlooking Horse Guards Parade with Charlotte and sons Prince George and Prince Louis.
The foursome could be seen enjoying themselves as they watched the ceremony but lip reading Nicola Hinckley claimed the Princess gave clear instructions to her daughter and her brothers.
Ms Hinckley told The Mirror that Kate appeared to say: “Keep smiling. And stay here for one moment.”
The Palace reiterated her appearance at the event on Saturday should not be considered a sign she will be resuming her official duties.
The Princess of Wales also thanked the public for the outpouring of support shown to her and the Prince of Wales since she announced her cancer diagnosis.
Her brief return to public life was greeted with loud cheers as she was spotted riding the Glass Carriage to Horse Guards Parade with George, Charlotte and Louis.
She later was reunited with William, the King and Queen on the balcony of Buckingham Palace to watch the RAF Red Arrows’s flypast.