The Queen's granddaughters Princess Eugenie and Zara Tindall shed tears as they and other senior members of the Royal Family inspected flowers left by mourners at Balmoral.
It is the first time they have been seen in public since the death of the Queen on Thursday.
The granddaughters were joined looking at bouquets by Prince Andrew, Princess Beatrice, Prince Edward, Sophie Countess of Wessex, their daughter Lady Louise Windsor, and Princess Anne on their way back from a private prayer service at nearby Crathie Kirk.
The Duke of York thanked people for visiting Balmoral after the death of his mother and was overheard saying: "We've been allowed one day, now we start the process of handing her on."
The family stopped to look at the flowers and read tributes, while Princess Eugenie was seen laying a bunch of flowers with the rest of the tributes.
The Duke of York at one moment was seen putting his arm around his daughter, Princess Eugenie, as she wiped a tear from her eyes.
Hearing one group of mourners who had come from Glasgow to show their support, Prince Edward said: "Thank you very much for coming all that way, we appreciate it."
Several of the Queen's relative are still staying at Balmoral after travelling there on news of the Queen's deteriorating health on Thursday.
Watch Sky News live from 10am as a cortege takes the Queen's coffin from Balmoral to Edinburgh
Prince William and Queen Consort Camilla travelled back to London with the new King to take part in the Accession Council as Privy Counsellors at St James's Palace.
The King began his momentous day by discharging the "sorrowful duty" of announcing the death of his "beloved mother", and told the council: "I know how deeply you, the entire nation - and I think I may say the whole world - sympathise with me in the irreparable loss we have all suffered."
The historic moment was televised for the first time, giving the world a first glimpse of the ancient ceremony that dates back centuries - and the decision to broadcast it to the public is one of the first changes to convention instigated by the new King.
The new monarch became King the moment his mother died, but an Accession Council must be convened following the death of a Sovereign - usually within 24 hours.
More than 200 privy councillors - a group of mostly senior politicians past and present, some members of the monarchy and other national figures - were present to hear the Clerk of the Council read the Accession Proclamation.
On Friday, King Charles III stopped to greet crowds gathered outside Buckingham Palace as he arrived in the capital for the first time as monarch.
He shook hands with countless members of the public.
Tearful and overwhelmed with emotion, people applauded and cheered the King during his 12-minute walkabout outside the palace gates, with several shouting "God bless you, Charles" and "God save the King".
One woman, Jenny Assiminios, even hugged and kissed the King on the cheek as he stopped in front of her, but the new monarch appeared to take it in his stride.