The duchess did not assume the role at Pippa's wedding in an effort to avoid drawing the attention away from the bride on her big day, and given that she is of a higher royal status than Markle, it would break protocol for her to assume a lesser role.
Meghan Markle's father will walk her down the aisle when the American actress marries Britain's Prince Harry this month and both her parents will meet Queen Elizabeth and senior royals in the run-up to the ceremony, Kensington Palace said on Friday.
Meanwhile, Ms Markle will not have a maid of honour and all of her bridesmaids and pageboys will be children.
The Duchess, who, let's just say has had tense relations with her former in-laws over the years, is invited to the main wedding and a first general reception, but will not be welcome at a second more intimate gathering of 250 guests hosted by Prince Charles later in the evening.
Ms Markle "has a very close-knit group of friends and did not want to choose between them", Kensington Palace's communications secretary Jason Knauf said.
It is also safe to assume that, as it is expected Prince George and Princess Charlotte will be page boy and flower girl, the duchess will be tending to her children and ensuring they're on their best behaviour as she did when they held the same roles at Pippa's wedding just a year ago.
It has also been revealed Harry will involve the family of his late mother, Princess Diana.
Queen Elizabeth's grandson Prince Harry marries his US fiancee Meghan Markle this month in a wedding expected to attract huge global interest. We doubt Doria is going to do anything to piss off the royal family, as she's to have a role in the upcoming royal wedding!
Mr Markle was a cinematographer, working on programmes including the 80s TV show Married with Children, when his daughter began her own acting career.
Cape Town - In less than two weeks Meghan Markle will be walking down the aisle in the dress of her dreams.
According to Samantha Grant, Ms Markle's half sister from her father's first marriage, their father Thomas was "completely self-sacrificing" and "the glue of our family".
Food stalls and big screens will be set up near to the Long Walk and viewing areas will be set up along the procession route.