See Princess Charlotte's Grown Up Gesture for Queen Elizabeth at the Late Monarch's Funeral

Princess Charlotte is honoring Queen Elizabeth in a special way as she says a final goodbye to her late great-grandmother.

The 7-year-old daughter of Prince William and Kate Middleton arrived at Westminster Abbey in London Monday, joining the royals and leaders from around the world for the state funeral of the late monarch. Dressed in all black, Charlotte matched her mother in a long coat and wore a hat for the first time. Headpieces are a staple for British women at formal events, marking a touching and grown-up gesture in honor of the Queen.

Charlotte also honored the Queen by wearing a small diamond brooch in the shape of a horseshoe, a tribute to her great grandmother's love for horses.

For the state funeral, Charlotte took part in the royal family procession behind the Queen's coffin alongside parents William and Kate and brother Prince George, 9, as the family made their way down the aisle of Westminster Abbey. Kate, 40, escorted the little ones into the service, though William, 40, arrived earlier alongside King Charles III.

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William and Kate spent last week carefully considering whether to include their eldest two children in the procession and service, PEOPLE understands. Prince George and Princess Charlotte have joined their parents at a number of royal outings, including at Westminster Abbey for great-grandfather Prince Philip's memorial service in March.

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After Queen Elizabeth's husband's funeral was scaled down due to COVID-19 government restrictions at the time, the memorial service provided a chance for more family and representatives from the various charities that Prince Philip was involved in to pay their respects.

George and Charlotte are several years younger than William was when he attended his mother Princess Diana's funeral in 1997 at the age of 15. Prince Louis, 4, was likely deemed too young to join the rest of the family for Monday's funeral.

Last week, Charles, 73, addressed the United Kingdom for the first time after the Queen died at the age of 96. Among the changes announced, Charles shared that Prince William and Kate had inherited the titles of Prince and Princess of Wales.

Their three children — who are now the second, third, and fourth in line to the throne — go from being Princes and Princess of Cambridge to being Princes and Princess of Wales. Therefore, they are now Prince George of Wales, Princess Charlotte of Wales and Prince Louis of Wales.