The movie, titled "Inquest," explores the conspiracy theories surrounding the death of Princess Diana.
The "Suits" alum wore it just days before her explosive tell-all interview with Oprah Winfrey.
In the infamous 1995 Panorama interview, Princess Diana spoke about her "crowded" marriage with Prince Charles.
Kate shared an old picture with her mother, Carole Middleton, on the occasion of Mother's Day in the UK on Sunday.
Prince Harry laid flowers on Princess Diana's grave while Prince William's kids made cards for their grandmother.
"I think it's the strength that causes the confusion and the fear," Diana said in the interview.
In the letter, Princess Diana expressed her longing "to hug the Queen."
The Duke and Duchess of Sussex fear the media attention could make their daughter's life difficult if they name her after Princess Diana.
The Duke of Sussex also subtly hinted that their family is complete and they are not going to try for another baby.
Prince William had also supported the decision to launch an independent investigation into the matter last year.
Meghan and Wallis are repeatedly compared to each other as the American divorcees both married British royals who stepped down from their royal duties.
The former actress reportedly mirrored Princess Diana by showing a "slightly enigmatic smile" on her face.
Meghan Markle and Prince Harry's interview with Oprah Winfrey is riddled with symbolic messages including that of revival and an homage to two Commonwealth countries.
In a recently-released teaser, Oprah is seen asking Meghan Markle, "Were you silent or were you silenced?"
Diana "wanted her children to be princes of a 'modern Crown' and would have been "furious" with Prince Harry over "Megxit."
The interview was Charles and Diana's first as a couple, and also the biggest media story at the time.
Their rift could be healed as long as Harry and Meghan don't make any personal attacks in their upcoming tell-all interview with Oprah Winfrey.
If it's a girl, Harry and Meghan can possibly name her Diana, as a tribute to his late mother.
While Harry and Meghan might stop at two children, William and Kate are already planning their fourth.
Jemima, a close friend of the late Princess Diana, briefly dated "The Crown" creator before he went back to Anderson.
One continuous theme throughout the entire discussion was that only British designers were chosen to design the royal wedding gowns.
A royal expert says that the way Prince Harry and Meghan Markle are behaving is "both childish and passionate."