Anne, the second eldest of the queen and Prince Philip's four children, was with the 96-year-old queen when she died Sept. 8 at Balmoral Castle, in Scotland, and on Monday was in the car behind the hearse as it traveled to Windsor, England.
In Windsor, Elizabeth will be buried at the King George VI Memorial Chapel at St. George's Chapel, alongside Philip, who died last year at the age of 99.
Anne, 72, was the only one of the queen's children to join each part of the journey from Balmoral to Windsor.
On Sept. 11, Anne and her husband, Sir Timothy Lawrence, were part of a very small convoy that escorted the queen's coffin on a more than six-hour drive from Balmoral to Holyroodhouse Palace in Edinburgh.
Anne was photographed curtseying to her mother's coffin as it arrived at Holyroodhouse.
The next day, Anne, dressed in military uniform, walked with her four siblings behind their mother's coffin in a procession from the palace to St. Giles' Cathedral, where it lied for 24 hours to allow people in Scotland to pay their respects.
At the cathedral, Anne made history by joining Charles and her two other brothers, Princes Andrew and Edward, in holding vigil at their mother's coffin.
The tradition, known as Vigil of the Princes, had previously been carried out by male-only royal family members, making Anne the first female member to take part.
On Sept. 13, Anne flew with the queen's coffin from Edinburgh to London, where it traveled to Buckingham Palace.
In London, Anne joined her siblings Charles and Princes Andrew and Edward in a procession to Westminster Hall, where the queen lied in state for four days.
She later joined her siblings in standing vigil at the queen's coffin inside the hall, where hundreds of thousands of people came to pay their respects to Britain's longest-reigning monarch.
"I was fortunate to share the last 24 hours of my dearest Mother’s life. It has been an honour and a privilege to accompany her on her final journeys," Anne said in a statement last week. "Witnessing the love and respect shown by so many on these journeys has been both humbling and uplifting."
"We will all share unique memories. I offer my thanks to each and every one who share our sense of loss," she continued. "We may have been reminded how much of her presence and contribution to our national identity we took for granted. I am also so grateful for the support and understanding offered to my dear brother Charles as he accepts the added responsibilities of The Monarch."
Anne ended her statement with poignant words of appreciation, writing, "To my mother, The Queen, thank you."
What to know about Princess Anne
The sight of Anne by her mother's side on her final journey was a striking and fitting image given the close bond the princess was known to have shared with her mother.
In becoming a mom of two with her first husband, Mark Phillips, Anne gave the queen and Philip the first two of their eight grandchildren, Peter Phillips and Zara Phillips Tindall.
Anne chose not to give her two children royal titles when they were born, an option she would have been given by the queen had she wished to do so.
She told Vanity Fair in an interview two years ago to mark her 70th birthday that she thought it was "easier" for her children to go through life without HRH titles.
"I think it was probably easier for them, and I think most people would argue that there are downsides to having titles," Anne said. "So I think that was probably the right thing to do."
Like the queen, Anne is known for her love of horses, a passion that led to her competing in the 1976 Montreal Olympics.
Anne was the first member of Britain's royal family to compete in the Olympics. She rode her mother's horse, Goodwill, in the three-day equestrian event in Montreal, according to the royal family's website.
Nearly four decades later, Anne's daughter, Zara Phillips Tindall, competed in the same event at the 2012 London Olympics and won a silver medal for Team Great Britain.
In addition to sharing a passion for horses, Anne shared a devotion to royal service with the queen, who met with Britain's new prime minister at Balmoral just two days before her death.
Anne is described on the royal family's website as having "one of the busiest working schedules of any member of the royal family."
Because Anne was born as the only girl among three brothers, she was leap-frogged in the line of succession, where she is now 16th in line to the throne.
In 2013, a law called the Succession to the Crown Act ended the centuries-old practice of a younger son superseding an elder daughter in the line of succession, but the law only applies to royals born after Oct. 28, 2011.
Like the queen, Anne started her royal work at a young age -- in Anne's case at the age of 18 -- and never stopped.
She is currently involved with over 300 charities, organizations and military regiments in the U.K. and around the world, according to the royals' website.
Anne has also helped to create several charities, including The Princess Royal's Trust for Carers, which supports caregivers in the U.K., and Transaid and Riders for Health, which each work to help people in developing countries by solving transportation difficulties.
When the queen began to reduce her workload in her later years, Anne stepped up her own duties even more, picking up engagements from the queen and in other cases joining her mom.
In one recent funny memory, Anne coached the queen on how to do a video call while working from home during the coronavirus lockdown.
"Can you see everybody?" Anne asked the queen, then 94, at the start of a June 2020 call with four carers during Carers Week in the U.K. "You should have six people on your screen."
When the queen replied that she could only see four people on her screen, Anne replied with a laugh, "OK, fair enough. Actually, you don't need me. You know what I look like."
Now in the wake of her mother's death and her brother's accession to the throne, Anne is expected to continue her service as a senior working royal, joining Queen Camilla, Prince Edward and his wife Sophie, the Countess of Wessex, and Prince William and his wife Kate, the Princess of Wales, in building the next chapter of the monarchy.