Pinned just below her left collar, Ferguson, 62, wore a shining brooch depicting a swooping swallow, a bird that was particularly popular with Victorians in England.
“Swallows are an indication that land is nearby and according to legend they can lead ships home and prevent them from getting lost,” reads a description of similar pieces on the site of the fine jewelry brand Elmwood’s, which is based in the Notting Hill section of London. “Thanks to this legend, swallow brooches were often given to loved ones when they set out on a journey to keep them safe so they returned home safely.”
That symbolism is certainly appropriate for Fergie — as she has been affectionately known since the 1980s — to display as she said goodbye to the Queen, who died at age 96 on Sept. 8 at her Scottish residence, Balmoral Castle.
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“I think to myself that honestly, my mother-in-law has been more of a mother to me than my mother,” Fergie, who was married to the Queen’s son Prince Andrew before they divorced in 1996, said last year on the Tea with Twiggy podcast. (The Duchess’s mother, Susan Barrantes, left the family when Fergie was a child to move to Argentina with a new husband, professional polo player Héctor Barrantes. She died in a car crash in 1998.)
Despite their split, Fergie and Andrew have remained close over the years, sharing two daughters, Princess Beatrice, 34, and Princess Eugenie, 32, who also attended services for the Queen on the final day of public mourning for the monarch who reigned 70 years.
The princesses’ parents still live together at their family home, Royal Lodge, in Windsor, close to the Queen’s final resting place in the King George VI Memorial Chapel, part of St. George’s Chapel, within the walls of Windsor Castle.
“I absolutely admire the incredible way Her Majesty is so modern,” Fergie said during the podcast appearance, “and how flexible, and how understanding, and how forgiving and how generous.”
Fergie has also called the Queen her “greatest mentor” and the “person who believes in me.”
According to Antique Animal Jewelry, which specializes in rare and unusual Victorian and Georgian pieces, swallows also “signify love and constancy across both distance and time.”
“Swallows are birds known to mate for life, and they always return to their nests after time away,” the jeweler says of the imagery, which is considered a charm that is meant to indicate wishes for a loved one to “safely return home.”
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Following the Queen’s death, Fergie shared a touching tribute to the monarch on Twitter.
“To me, she was the most incredible mother-in-law and friend. I will always be grateful to her for the generosity she showed me in remaining close to me even after my divorce,” Fergie wrote. “I will miss her more than words can express.”
A source recently confirmed to PEOPLE that Fergie and Prince Andrew would be adopting and caring for the late monarch’s two dogs. “The corgis will return to live at Royal Lodge with the Duke and Duchess. It was the Duchess who found the puppies, which were gifted to Her Majesty by the Duke,” the insider said.