It's been a difficult month for Lady Louise Windsor, 18, who lost her grandmother the Queen just days after starting at St. Andrews University.
SEE: Lady Louise Windsor rushes back from St Andrews for special service for the Queen
The teenager, who is the daughter of Prince Edward and Sophie Wessex, now faces her most important royal role yet, with Queen Elizabeth II's eight grandchildren standing vigil at her coffin on Saturday. Lady Louise will be joined by her brother, James Viscount Severn, and her cousins the Prince of Wales, Prince Harry, Princess Beatrice, Princess Eugenie, Zara Tindall and Peter Phillips for the sombre occasion.
WATCH: Everything you need to know about Lady Louise Windsor
The emotional vigil will last 15 minutes, with the Prince of Wales at the head of the coffin and the Duke of Sussex at the foot.
MORE: Where was Lady Louise as Prince Edward and Sophie Wessex rushed to Queen's bedside?
READ: Countess Sophie's life-threatening birth with Lady Louise Windsor revealed
Zara Tindall and Peter Philips will either side of the Prince of Wales, while Princesses Beatrice and Eugenie will be either side of Prince Harry.
Lady Louise and James Viscount Severn will be at the middle of the coffin, opposite one another.
Lady Louise recently started at St Andrews University
At King Charles III's request, both William and Harry will be in uniform. The other grandchildren will be in morning coats and dark formal dresses.
LOOK: Why the Queen's funeral venue is so special to the late monarch
The grandchildren are following in their parent's footsteps, who held their own vigil on Friday night, and this marks a big step for Lady Louise, who rarely attends public engagements and is out of the public eye the majority of the time.
Lady Louise and her brother, James Viscount Severn
The young royal paid her respects to her late grandmother on Wednesday, performing a curtsy at Westminster Hall, in front of Queen Elizabeth II's coffin.
Lady Louise made the move as a mark of respect to the late monarch, alongside her younger brother James, who bowed his head in respect for Her Majesty.
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