The royal couple have two boys and a girl: Prince George, 5, Princess Charlotte, 3, and Prince Louis, 6 months.
Kate is known for her wonderful style and unfailing elegance as she carries out public duties.
But sometimes she is spotted with a rather less glamorous accessory – but why?
The Duchess of Cambridge is often spotted wearing a plaster on her hand to cover up minor injuries.
She was most recently seen sporting one when she accompanied her husband to the Tusk Conservation Awards in London this month.
It was on the middle finger of her right hand, and, although she tried to hide it, it was clearly visible.
It’s far from the first time the Duchess has been seen with the protective covering.
In December 2016 she was seen wear a plaster on her left thumb as she attended the Christmas service at St Mark’s Church in Berkshire.
In November of the same year, she had a big plaster across the body of her left hand when she visited the Nelson Trust Women’s Centre.
In August 2016 she had a plaster on the thumb of her right hand – visible as she waved to admirers.
According to the Daily Mail, Kate has been wearing plaster in public since 2008, three years before she married Prince William.
When Buckingham Palace was asked in 2016 about the presence of a plaster they said: “We have no comment on the plaster,” reported The Mirror.
However, most likely Kate receives just as many cuts and scrapes as the average mother-of-three.
Unlike the majority of UK mothers, however, Kate does employ a nanny to help look after her children.
The little princes and princess are cared for by Maria Borrallo, from Palencia in northern Spain, who trained at the prestigious Norland College.
Writer Louise Heren, who co-wrote a book about Norland nannies and spent a year at the college making a TV documentary, said Maria would earn around £38,000-a-year as a live-in help to Kate and William’s growing brood and will have been trained not to impose strict rules.
It is expected she would have agreed on a regular routine of bath times and bedtimes for the children with the Duke and Duchess of Cambridge.
William and Kate took on Maria in 2014 to replace Jessie Webb, William’s former nanny who was brought out of retirement to help the couple after George was born.
Maria enjoys a private area of Kensington Palace, including a bedroom, lounge, kitchenette and bathroom.