The official Clarence House account wrote: “Happy Birthday to the Duchess of Cambridge!”
The official Kensington Palace Instagram account, which represents the Duchess and her husband, Prince William, shared a new portrait of the birthday girl.
The photo was captioned: “Thank you for your kind wishes on the Duchess’ birthday.
“Birthdays have been very different in recent months, and our thoughts continue to be with all those working on the front line at this hugely challenge time.”
Speaking to Express.co.uk, energy insights reader Angela Ward explained the Duchess’s body language also exhibits how she, like millions of others, are growing weary of the challenging times presented by the Covid pandemic.
The energy insights reader said: “As soon as I saw this picture of Kate Middleton, I was drawn to her gloved hand.
“Energetically, she is saying she wishes this time to be over. I feel intuitively she has had enough of these challenging times.”
But she said the new photo also shows how much she has grown in herself and her role.
Although she saw her parents, Carole and Michael Middleton, on her 38th birthday in 2020, that likely didn’t happen this year due to the ongoing pandemic.
It was reported the Duchess enjoyed a “quiet birthday” in her countryside home where she was thrown a “tea party” by the children.
A friend of the Duchess told Vanity Fair: “Catherine isn’t one for lots of fuss or big parties – being with William and the children is her favourite way of spending her birthday.”
While the Duchess is undoubtedly enjoying her downtime at home with Prince William and the kids, she’s also looking forward to getting back to her all-important early years work.
Royal author Ingrid Seward said: “Kate will want to get straight back to work, which won’t be easy with her little ones at home, but she has shown how important her work is to her.
“It’s not just shaking hands, she’s got to the root of the Early Years campaign and she’s going to be doing much more in this area.”
With many members of the Royal Family being in the at-risk category for Covid, the Duke and Duchess have had to step up and be front-and-centre.
Ms Seward added: “2020 was a big year for William and Kate. They emerged from it more popular than ever, but it was also important for them as a private couple.
“With such busy diaries, they don’t actually get much time together and this has been an exceptional year. The lockdown has meant they’ve had more time together and this has brought them closer together.”