The royal, who has had a troubled relationship with the monarchy, was pictured smiling as she walked beside her ex-husband, the disgraced Duke of York.

For the second year in a row, Andrew made the walk from Sandringham to church with the other royals.

The service at St Mary Magdalene Church is normally reserved for close royal relatives.

Sarah has not joined the family at church for many years, although it is thought in recent years she has been a guest at Sandringham for Christmas lunch.

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She was last seen walking to church with members of the family, including Queen Elizabeth II, in the early 1990s.

Sarah has won plaudits recently for speaking openly about her breast cancer treatment and urging women to get screened.

The King and Queen led the traditional procession to the church, where the road was thronged with more than 2,000 people.

Many had waited for hours to get a prime spot to see the royals.

After the service, Andrew and Sarah joined the King and Queen, as well as the Prince and Princess of Wales, to meet the waiting public during a walkabout.

Andrew could be seen laughing and throwing up his hands as he joked with well-wishers and the Duchess collected flowers and spoke to many of those waiting.

Andrew's alleged links to convicted sex offender Jeffrey Epstein will come under further scrutiny in the new year with the release of hundreds of files from a defamation case.