Kate Middleton is very grateful for Lady Gabriella’s help with her Christmas Carol Service

Kate Middleton is very grateful for Lady Gabriella’s help with her Christmas Carol Service

Gabriella marked her first Christmas without late husband Thomas Kingston by assisting Kate with ‘Together at Christmas’.

Kate Middleton is very grateful for Lady Gabriella's help with her Christmas Carol Service

Kate Middleton had an extra set of hands working on her Together at Christmas carol service this year.

The Princess of Wales, 42, wanted the fourth annual service to be focused around love, kindness and empathy — and she asked Lady Gabriella Kingston (née Windsor) to join her team to help, PEOPLE confirms.

Kate Middleton is very grateful for Lady Gabriella's help with her Christmas Carol Service

Gabriella, the only daughter of Prince and Princess Michael of Kent, played an advisory role around the music performances featured in the Dec. 6 service, PEOPLE understands.

And the 43-year-old royal, who works as a freelance journalist, enjoyed her role and was excited to be a part of the service, a source tells PEOPLE.

Kate Middleton is very grateful for Lady Gabriella's help with her Christmas Carol Service

Kate “was incredibly grateful for her contribution,” the insider adds.

Gabriella’s role in the service was fitting for the royal, who previously showed off her musical chops in 2020, when she released two songs to benefit music nonprofit Playing for Change Foundation.

Kate Middleton is very grateful for Lady Gabriella's help with her Christmas Carol Service

In addition to her role in planning it, Gabriella also attended the festive, candle-lit event — which was held at Westminster Abbey on Dec. 6

and airs on Christmas Eve on ITV1 and ITVx in the U.K — along with Princess Kate, Prince William, and their kids, Prince George, 11, Princess Charlotte, 9, and Prince Louis, 6.