The Duchess of Cambridge was quizzed about the length of time it took her husband to propose when she met youngsters benefiting from creative arts workshops in a children’s hospital.

William asked Kate to marry him after the couple had been dating for around eight years – asking her to be his wife in the romantic setting of Kenya.

Sarah Ibendahl brought up the subject and sympathised with the duchess, as it took her husband Ralph the same length of time before he asked her to tie the knot.

Kate met the mother during a visit to the Evelina London Children’s Hospital in central London, to learn about the creative workshops run by the National Portrait Gallery for young patients and their siblings.

When she first arrived, the blustery wind threatened to whip up the skirt of her Dolce & Gabbana tweed suit, and she pulled a face of surprise as she held it down.

After a brief indoor walkabout meeting families in the hospital’s reception, she sat down with children and art educators in the hospital’s third-floor atrium, as they created characters for a paper stage using Polaroid photographs of themselves – and the royal posed for an instant picture.

Royal visit to Evelina London Children’s Hospital
The Duchess of Cambridge arrives to visit a creative workshop (Yui Mok/PA)

Mrs Ibendahl, from Blackheath, south-east London – whose three-year-old son Benjamin is being treated for an auto-immune condition, said after meeting the duchess on a ward: “We also bonded over the fact it took our husbands like nine years before they asked us to marry them.

“When I mentioned it she laughed politely and gave a knowing smile.”

William and Kate met as students at St Andrews University in 2001 but did not start dating until a few years later – and the duke proposed to his then girlfriend in October 2010, with the couple marrying the following year.

Royal visit to Evelina London Children’s Hospital
The Duchess of Cambridge visits a creative workshop run by the National Portrait Gallery’s Hospital Programme at Evelina London Children’s Hospital (Toby Melville/PA)

Mrs Ibendahl explained how her son had a slight cold which developed into an auto-immune disease, which has meant he has lost the use of his legs.

She said: “He’s having ongoing treatment, it takes them a while to stop the pain, stop the disease progressing and for them to remember how to walk.

“Almost everyone makes a full recovery, it just takes time.”

Schoolboy Luke Wheeler-Waddison, 10, took Kate’s portrait photograph with an instant camera, as he worked on characters for his mini stage with his sister Savannah, four.

Luke was treated as a baby at Evelina London for a congenital heart defect and requires yearly check-ups.

Duchess of Cambridge
Kate helps a child during a creative workshop (Toby Melville/PA)

He recently broke his arm, which needed surgery, and showed Kate his scars where the plates and pins were fitted.

He was joined by his parents Joanne Wheeler, 47, and Anthony Waddison, 42, from Rainham, Kent and presented Kate with a rag wreath that he had made.

Luke said: “She was touched when we gave her the wreath, she said she would love to have the wreath up in Charlotte’s room.

“Not many people see a princess in real life and she’s going to be a queen one day, so it’s really exciting.”

Kate is patron of both the Evelina London and the National Portrait Gallery, with the art institution running a programme that supports the health, happiness and wellbeing of patients at four children’s hospitals across London.

Duchess of Cambridge
The creative workshop is run by the National Portrait Gallery’s Hospital Programme (Toby Melville/PA)

The gallery delivers 60 workshops a year, inspired by portraits and stories from its collection, working alongside play therapists, nurses and hospital teachers.

Kate also played with the 13-month-old child of a mother who was told on Monday that her daughter has a rare genetic disorder called glycogen storage disease, which means she will need to be fed every three hours for life to avoid a hypoglycemic attack.

Emily Parker, from Portsmouth, said Kate told her Prince Louis liked his knees tickled, after she tickled her daughter Rose.

Speaking about her daughter’s condition, she said: “She was completely healthy, then on Boxing Day went bright yellow, and we took her to A&E and they said her liver’s gone, and we thought she wasn’t going to make it.”

She later feared her daughter would need a liver transplant, but with treatment she rallied, and Ms Parker said the royal visit was a welcome relief.

Ms Parker said: “I’m trying to be cool about this, but she’s my favourite person, and we’ve had some really dark times as a family and this is perfect.

“When I look back at this horrible experience I’m just going to remember all the nice things, and for her to take the time to come and see us is great.”