Prince Harry and Prince William could reunite ahead of their father's coronation on 6 May.
A spokesperson for the Sussexes confirmed this week that they have been invited by King Charles to the historic event – although they have not yet decided whether they will attend.
An announcement was placed in the Telegraph this week confirming the passing of the brothers' great-aunt. It read: "The Hon Mary Cynthia Burke Roche, peacefully at home on 3rd March, aged 88."
Mary was one of Princess Diana's aunts, the older sister of her mother, Frances Shand Kydd, who passed away in June 2004. It is not known when Mary's funeral will take place, but the Princes will likely want to attend to say their final goodbyes.
Mary had a good relationship with her niece Diana and later spoke of her ill-fated marriage to then-Prince Charles.
At the time of their wedding in 1981, Diana was just 20 while her husband was 33. "They were at very different stages of development," she explained.
"Diana was young and had limited life experience, and Prince Charles was already a great thinker. He read a great deal. They were, perhaps, different people."
TOP STORY: Sarah Ferguson has surprising response when asked about Harry and Meghan
TRENDING: Monarchs who have stripped grandchildren of royal titles – just like Queen Margrethe
DISCOVER: Six times royal brothers have fallen out
Just last week, Diana's brother Charles Spencer shared a striking snapshot of his mother and Mary together – and fans were struck by the family resemblance.
"Diana looks so much like your Aunt Mary!" one exclaimed while a second echoed: "Your Aunt Mary looks very much like our beloved late Princess of Wales Diana."
And a third shared: "What a strong family resemblance connecting the Spencer family! Lovely picture."
Meanwhile, royal fans are speculating whether Harry and Meghan will make the trip to attend the coronation. It comes after confirmation that King Charles had asked the couple to leave their UK home, Frogmore Cottage, with the couple now living permanently in Montecito.
LISTEN: King Charles' adventures from the cockpit while piloting planes
Make sure you never miss a ROYAL story! Sign up to The Royal Explainer newsletter to receive your weekly dose of royal features and other exclusive content straight to your inbox.