Meghan Markle and Sophie Wessex are set to follow the Queen 's funeral procession in a car - while senior royals will walk directly behind the coffin.
Plans for the late sovereign's state funeral were unveiled yesterday afternoon, with a detailed schedule for the historic occasion on Monday now made public.
King Charles is expected to lead members of the Royal Family behind the Queen's coffin at around 10.44am as they complete the final stage procession from Westminster Hall to Westminster Abbey.
Both The Duchess of Sussex and the Countess of Wessex will meanwhile travel to the service closely behind in a shared funeral vehicle.
It will be the second time they have attended a royal occasion together in the past week, with the pair both travelling in the same car to Westminster Hall for the Queen's lying-in-state on Wednesday.
The Queen's State Funeral will begin at 11am, conducted by Dean of Westminster. Around midday, the national anthem and a lament played by the Queen's piper will bring the service to an end.
Sophie Wessex, who married Prince Edward in 1999, shared a unique bond with her mother-in-law and was often referred to affectionately as her 'second daughter '.
She is now tipped to take on a number of roles left by late monarch after winning her trust over the years.
A royal source said: “The Queen and the countess had a fantastically warm and joyful relationship.
“Her Majesty admired Sophie’s quiet sense of duty, her strong work ethic and the way she balanced her public and family lives. They also shared many of the same interests.
“The Queen’s decision to pass on these patronages reflects the closeness of their bond.
“Sophie’s growing popularity with the public is also evident and she will take on a larger public profile in a new-look monarchy of King Charles.”
Sources suggest the patronages earmarked for Sophie to take over include the Women’s Institute and Dogs Trust.