The former actress was referred to as “Ms Markle”, instead of the honorific “Miss”, as was the case for Kate Middleton.
Etiquette expert William Hanson told the Sun Online the Queen does not normally acknowledge the title “Ms”.
He said: “The Royal Household, in particular The Queen, has never before acknowledged the honorific Ms, regardless of whether it was being used to signify a divorced woman or one who did not feel her marital status was of importance.
“It was first used in connection to Meghan in the November engagement announcement and since then has been used throughout the royal household’s communications, on press releases, invitations and social media.
“I would imagine Meghan herself has asked to be styled accordingly and that there is no slight intended on Prince Harry’s finance.
“It is another subtle sign that the royal household is moving with the times.”
Earlier this month, it was reported the Duchess had given her name as “Rachel Meghan Her Royal Highness The Duchess of Sussex” when Archie Harrison Mountbatten-Windsor was registered after his birth in May 2019.
However, according to The Sun, the certificate was amended on June 6 that year to remove her first names “Rachel Meghan”.