Christmas night out with her nieces: Zara Tindall leaves Mike Tindall at home with the kids as she joins her brother Peter Phillips and his children Savannah and Isla at Kate’s carol concert

Savannah and Isla Phillips captured the hearts of the nation when they attended the Christmas carol concert curated by the Princess of Wales, which aired last night.

The girls were accompanied by their father Peter Phillips, cousin of King Charles III, and their aunt Zara.

Savannah, 12, and Isla, 11, looked calm and confident as they smiled for the cameras as they entered Westminster Abbey.

Zara, 41, wearing an elegant purple coat, attended the concert without her husband Mike Tindall, who stayed home with their three children.

It happened ahead of the King's speech, which will be broadcast at 3pm on Christmas Day.

Savannah, Peter and Isla Phillips arrive at Westminster Abbey with Zara Tindall

Zara looked radiant in a deep purple winter coat. She accessorized the outfit with a matching pair of shoes with statement earrings and a crocodile leather bag, with her hair pulled back in a bun.

The mother of three opted for a simple yet elegant makeup look for the occasion, complete with a nude lip and a touch of eyeliner.

Mia, Lena and Lucas Tindall all stayed home.

Peter Phillips wore a smart suit, while his daughters donned dresses, black ballet pumps and elegant jackets: a camel number with a fur collar and a simple black with gold buttons.

They both smiled as they arrived at the abbey, flanked by their father and aunt.

The aim of the concert was to 'recognize the selfless efforts of communities across the UK and highlight the importance of coming together to support each other'.

Led by the Princess, it is designed to bring people of all faiths (and none) together by combining both traditional and modern elements.

The Royal Carols: Together at Christmas service was broadcast on ITV on Christmas Eve.

Savannah Phillips wore a red dress and camel coat, complete with black tights and black ballet pumps

The service saw the world-famous Westminster Abbey choir perform some of the country's best-loved Christmas carols, alongside musical performances from guests including Jacob Collier, Freya Ridings and James Bay, and a special duet from Beverley Knight and Adam Lambert.

There were also moving talks from speakers including Prince William, Michael Ward, Emma Willis, Roman Kemp and Jim Broadbent.

A specially commissioned poem written by Joseph Coelho, the Children's Laureate, was read by Leonie Elliott.

The King and Queen will celebrate Christmas Day with other members of the Royal Family at Sandringham.

Traditional royal festivities will once again take place at Norfolk's private estate.

Charles and Camilla are expected to be joined by the Prince and Princess of Wales and their children Prince George, Princess Charlotte and Prince Louis for the morning service at St Mary Magdalene Church.

Zara Tindall (pictured) was the epitome of elegance and glamor as she stepped out in her festively colored ensemble this evening

Zara Tindall (pictured, right), King Charles' niece, was pictured arriving at the house with her brother Peter Phillips (pictured, left)

The King and Queen, along with the Princess Royal and her husband, Vice Admiral Sir Timothy Laurence, waved to well-wishers as they attended a Christmas Eve service at the church on Sunday.

Royal Christmas holidays traditionally include greeting people outside the church, and a family lunch with turkey and all the trimmings.

Sandringham House has been the private home of four generations of British monarchs for more than 160 years and is now owned by the King.

Later on Christmas Day, the King will deliver his second annual address to the nation at 3pm, with a focus on the environment.

The speech will be given in a room at Buckingham Palace and will take place next to a live Christmas tree, which will then be donated to charity to be replanted.

King Charles is expected to speak about the need to protect the planet, a turn away from his mother's carefully apolitical speeches.