The Duke and Duchess of Cambridge met children who are coming to terms with the loss of a loved one as they visited the headquarters of Child Bereavement UK.
William and Kate chatted to the youngsters who, with the help of the charity, are learning to rebuild their lives following the death of a parent or sibling.
Staff and supporters of the organisation were given a boost by the visit on Tuesday of the Duke, royal patron of Child Bereavement UK, and his wife who is five months pregnant.
Kate wore a coat by Goat, a luxury cashmere designer fashion label, and a dress from high street store Top Shop.
The royal couple went on a brief walkabout when they arrived meeting some of the well wishers who lined the entrance of the charity's offices in Saunderton.
Kate was given a present by little seven-year-old Adam White, who handed over a toy rabbit for the royal baby and a chocolate bar for the Duke, and as she took them the Duchess said: "I'll make sure William gets it."
Amongst the charity's supporters was baking queen Mary Berry, who has raised money for the charity on BBC2's Celebrity Cash in the Attic after her 19-year-old son William died in a crash in 1989.
The Duke joked with the TV cook how his wife loves her books and his stomach loves her recipes, when they met during a visit to a bereavement charity.
William and Kate went on separate tours of the charity's Buckinghamshire offices when they first arrived, visiting the departments handling training, bereavement services and fundraising.
Berry was with the charity's marketing and fundraising team and the Duchess, who wore a black short-sleeved shift dress with a cream collar from Top Shop, told the cookery writer: "I'm a big fan of your cook books and your cakes."
A few minutes after the Duchess had left, William appeared in the doorway and he told the TV chef: "My wife is a big fan of yours, and my tummy's a big fan."
The Duke carried on joking with Berry, saying: "I think I need some lessons. You've been very busy racing around the country feeding the population," before telling her he loved "chocolate brownies".
William said her show allowed families to turn off the TV and do something together, but Berry made the room roar with laughter when she replied: "As long as you turn it on for the baking."
Ann Chalmers, the charity's chief executive, said: "The Duke takes a keen interest in our work supporting bereaved families and training the many professionals working at the front line of bereavement support."
She added: "It has been a privilege to have the Duke of Cambridge lend his support to our work; his involvement has made a huge, positive difference to Child Bereavement UK."
Losing his mother Diana, Princess of Wales at the age of 15 has given the Duke an acute understanding of childhood bereavement.
Diana died in 1997, following a Paris car crash, and the teenage William was comforted by his family but also had to endure his grief in the public gaze.
The Royal has described how following her death the word "mummy" became hollow for him.
When William attended the launch of the organisation's Mother's Day campaign in 2009, the year he became the charity's royal patron, he said: "Never being able to say the word 'mummy' again in your life sounds like a small thing.
"However, for many, including me, it's now really just a word - hollow and evoking only memories."