The Princess of Wales has been sent "hundreds of letters and cards" from around the world as she continues to recover from abdominal surgery in hospital.
The future Queen was admitted to The London Clinic last week for a significant operation, where she continues to recover.
Catherine's condition is understood to be "non-cancerous".
Her Royal Highness is expected to stay in hospital for the next week or so, before convalescing at her home in Windsor for up to three months.
The Princess of Wales has been in hospital for over a week.
PA
It is understood The Princess has received "hundreds of letters and cards", not just from the UK, but from around the world, since Kensington Palace announced her unexpected health news a week ago.
The Princess of Wales is one of the most popular members of the Royal Family with the British public, according to the latest YouGov poll.
The Princess is not expected to return to official public duties until after Easter, but it is understood work on her early childhood campaign is continuing.
Royal staff continue to busy themselves behind the scenes on causes close to her heart.
The Princess of Wales is one of the most popular members of the Royal Family with the British public, according to the latest YouGov poll.
PA
In January last year, Catherine launched 'Shaping Us' - a campaign designed to raise public awareness about the importance of the first five years of a child's life and the impact it has on their future adult selves.
This month, bosses of some of the UK's biggest businesses met at Kensington Palace to "lead the charge in driving transformative change and creating a healthier, happier society by increasing the focus on early childhood."
Prince William is understood to be splitting his time between being by his wife's side in hospital and looking after their three young children in Windsor.
The Prince of Wales' public duties have also been put on hold.
The Princess is not expected to return to official public duties until after Easter.
PA
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Royal fans were quick to jump to William and Catherine's defence online.
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Royal fans were quick to jump to William and Catherine's defence online, who have become a target of relentless social media trolling, and criticism from republic campaigners.
Last week, Kensington Palace said the Princess "hopes that the public will understand her desire to maintain as much normality for her children as possible".
"The Princess wishes to apologise to all those concerned for the fact that she has to postpone her upcoming engagements. She looks forward to reinstating as many as possible, as soon as possible."