The Duchess of Cambridge celebrated her 39th birthday on January 9 in style - with a nice hot cuppa.

Instead of marking the occasion with a weekend house party with friends at her country home of Anmer Hall like every other year, Kate is said to have spent a "quiet birthday" having a tea party organised by William and their three children George, Charlotte and Louis.

William is said to be an expert when it comes to fixing the perfect cup of tea - and it sounds he's taken the opportunity to train up the royal children in the art of the cuppa amid lockdown.

A source previously told People Magazine that if you visit the Duchess, you're sure to be offered a cup of tea.

"It's often William who makes it! It's a lovely, welcoming house, not a fancy, stuffy palace in any way."

The Queen, Charles and Camilla all offered birthday wishes to Kate on their social media.

The official Royal Family account posted two photos of Kate, writing, "Wishing the Duchess of Cambridge a very happy birthday today!"

Charles and Camilla shared another snap of the mum-of-three, writing, "Happy Birthday to the Duchess of Cambridge!"

Kate normally celebrates on the weekend closest to her birthday by throwing a shooting party and hosting her closest friends and family, including her parents Carole and Michael.

Last year, William and Kate welcomed guests to a weekend-long celebration including a Sunday morning church outing with the Queen at St Mary Magdalene Church.

The Cambridges thanked friends and family for their birthday wishes in a following post on Instagram, acknowledging that it's a rough time of year for those celebrating their birthdays in England, which has gone back into lockdown for the third time.

"Thank you for your kind wishes on The Duchess' birthday," they wrote on the Kensington Royal account.

"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 challenging time."