Sarah and Andrew were married in 1986, with the Duke and Duchess of York going on to separate in 1992 before their 1996 divorce.
However Fergie has remained close to her ex husband, with whom she shares two daughters - Princess Beatrice, 31, and Princess Eugenie, 29.
And with the Duchess of York being vocal in her support of the Duke over his recent widely-criticised BBC Newsnight interview, and subsequent resignation from royal duties, she has found herself in the firing line, too.
Which is where Camilla has the opportunity to use her friendship with Fergie for the good of the royal family.
It isn't the first time she's stepped in, as back in 2016, it was reported that Camilla played a key role in helping Fergie regain her royal standing, which was at a particular low after being excluded from Kate Middleton and Prince William’s 2011 royal wedding.
The Duchess of Cornwall even reinstated Fergie as patron of her late brother’s charity, the Elephant Family, after Prince Charles had kicked her out.
According to a source who spoke to the Daily Mail in 2016: “Camilla adored her brother and so is instinctively fond and slightly misty-eyed about anyone who helped him out, as Fergie did as patron and long-standing supporter of the charity.”
The royal source continued: "Camilla is a peacemaker by nature – look how she managed to get the Queen, William and Harry on side after the most inauspicious of beginnings.
“She’s also befriended Kate. Having been vilified herself for so long, she has much sympathy for Sarah.”