The duchess joined more than 300 mourners at the funeral of Carolyn Cotterell, who died from cancer earlier this week.

It was a tearful day for the duchess and Princesses Beatrice, left, and Eugenie

The 40-minute Requiem Mass was held at Belmont Abbey just a few miles from 43-year-old Mrs Cotterell's home.

The duchess attended the service with her daughters, Princesses Beatrice and Eugenie.

Mrs Cotterell was Princess Beatrice's godmother, while the duchess is godmother to her 11-year-old daughter Poppy.

Following the service a tearful duchess, who was wearing a dark grey, knee-length suit and hat, walked slowly back to her car holding hands with her daughters.

Daughter's tribute

A private internment was held at the village of Byford near the Garnons estate where Mrs Cotterell lived in the grounds with Harry, her husband of 13 years.

The 3,000-acre estate is the family home of Sir John and Lady Cotterell.

The service, which was conducted by Father Michael Evans, included three hymns and a reading by Mrs Cotterell's father John Beckwith-Smith.

Her daughter Poppy wrote a tribute to her mother which was printed in the order of service.

It said: "To find one thing about her I actually 'disliked' would be impossible because she was great. I know she has gone to a better place.

"She went through a lot of pain and would she ever complain? Never."

Regular visits

Mrs Cotterell and the duchess had been friends since childhood and shared a flat in Lavender Hill, north London, before they both married.

The duchess visited her friend regularly since she was diagnosed as having skin cancer 18 months ago.

Mrs Cotterell died at her home on Monday with her family around her. She leaves two other children, Richard, nine, and five-year-old George.

Earlier, Major Ron Ferguson sent a birthday message to his daughter, urging her to remarry the Duke of York.

He told GMTV: "They are so happy together, they make such a wonderful atmosphere at Sunninghill, you only have to be there to observe it - they are very, very happy together."