To lose one key aide may be regarded as a misfortune; to lose all of them looks like carelessness.
I can disclose that the Duchess of Sussex's right-hand woman is to become the latest member of her staff to quit.
Amy Pickerill, who was appointed as Meghan's assistant private secretary just last year, is to leave her post after the couple move to Frogmore Cottage in Windsor this month.
"Amy is leaving," a royal source confirms. "It's very sad for her colleagues, as she is a really popular member of staff."
The move is a shock as Amy was handpicked to work for Meghan and was tipped to succeed Samantha Cohen, who is due to step down as the Duchess's private secretary after 17 years with the Royal Family.
It is understood that Amy will be leaving the Royal Household altogether and moving overseas.
She has played an important role in introducing Meghan to royal life, organising charity projects such as the cookbook the Duchess published to help families affected by the Grenfell Tower disaster.
A friend of Amy insists she has a warm relationship with Meghan, adding: "She has agreed to stay on to help them with the birth of the baby and organise their new household, but will then move on."
Amy's departure will mean that all three of the main women working for Meghan will have left in a matter of months.
Last November, I disclosed that Meghan's PA, Melissa Touabti, had quit less than six months after the American actress married Prince Harry.
Like Melissa, Amy had to deal with the traumatic build-up to the wedding last May, in which the Duchess's father, Thomas Markle, gave a running commentary to journalists on the likelihood of his attending the ceremony.
He decided not to come just five days before the big day, leaving Harry to ask Prince Charles to step into the breach and walk Meghan up the aisle. Amy was pictured at Heathrow airport, picking up Meghan's mother, Doria.
Royal biographer Robert Jobson claimed in his book, Charles At Seventy, that Meghan's wedding preparations were so stressful that Harry became 'petulant and short-tempered' with members of staff.
He wrote: "Raising his voice on occasion, Harry would insist: What Meghan wants, she gets."