Kate Middleton to surprise fans at this year's Christmas carol service

Prince William's wife Kate Middleton will leave fans flabbergasted at this year's carol service at Westminster Abbey.

King Charles III and Queen Consort Camilla will honour the Prince and Princess of Wales by joining them for the annual service on December 15, the same day as the second instalment of Harry and Meghan's documentary airs on Netflix.

The mother-of-three won the hearts with her music skills at the last year event, and her video of playing piano with singer Tom Walker and his band went viral.

Walker gushed over Kate after the last year performance, saying: "Without doubt, it was a once-in-a-lifetime experience. I thought she absolutely smashed the performance; it's not easy to just jump behind a piano with a bunch of musicians you've never played with before and record live takes to camera, but she completely nailed it."

The Princess of Wales, who just concluded her amazing US trip, has geared up for this year's event. Kate, according to a source, is all excited and prepared for another surprise this year. 

The source adds that Kate's carol service might be a big blow to Meghan and Harry's recent drama as the Prince and Princess of Wales have done good planning for the day.