Markle unveiled a Christmas gift set from her Goop-style brand - two jars of honey sold with a black leather bookmark - exclusively at Godmothers, an upscale Montecito bookstore owned by friends Victoria Jackson and Jennifer Rudolph Walsh.

In accompanying Instagram images, the bookmark appears inside The Boy, The Mole, The Fox and The Horse, the bestselling book by Charlie Mackesy.

The placement was swiftly flagged by royal watchers as Mackesy worked closely with Catherine last year, creating bespoke illustrations for the order of service at Westminster Abbey for her annual carol concert.

In the promo shots, the bookmark sits on a page featuring the quote: "Always remember you matter, you're important and you are loved and you bring to this world things no one else can."