After the trio agreed on the final draft, she hand-wrote the letter to Thomas, which was ultimately published by the Mail on Sunday.
According to Markle's lawyers, the former actress was allegedly concerned about the narrative her dad Thomas Markle was creating in the media with "false" claims that she "had not even tried to contact him" and fully "abandoned him".
In the documents submitted to the court, Megan had to admit that she passed on personal information to the authors of the book "In Search of Freedom: Harry, Meghan and the Creation of the Modern Royal Family" Omid Scobie and Carolyn Duran.
It said she wrote the letter "in accordance with the advice that she had received".More news: Tigray forces fire three rockets into neighbouring region of Ethiopia
In 2019, the Duchess of Sussex filed a claim against Associated Newspapers, a parent company of The Mail on Sunday and Daily Mail, over the misuse of private information and breach of data protection act over the publication of her letter to her father back in 2018, shortly after her wedding to Prince Harry.
The newspaper also claims that the Duchess has cooperated with the Finding Freedom authors and allowed them to publish extracts from her letter to Thomas, something her father did in relation to the British tabloid. The document did not name the members of the royal family consulted by Meghan.
Once she had made a decision to write it, she informed her close confidante Jason Knauf, Kensington Palace communications secretary at the time, who had been speaking to Mr Markle on a regular basis in the run-up to her wedding.
Meghan's lawyers said she showed a draft of the letter to her husband and to Knauf, and that Knauf provided "feedback on the draft but no actual wording".More news: Watch SpaceX launch a satellite that will monitor the world's oceans
After he moved to the United States with wife and son, Archie, the Duke has headlined a series of projects.
The wife of Prince Harry is now suing The Mail on Sunday, a United Kingdom newspaper, for breach of privacy for printing out extracts of a handwritten letter she had sent to her estranged father back in 2018.
The document also reveals that the duchess allowed an unnamed individual to speak to the authors of a biography of the Sussexes to prevent "further misinformation" being spread about her relationship with her estranged father.
Meghan's legal team said in the documents: "Given the claimant's level of distress surrounding the form, frequency and content of the media coverage concerning her father, and as the newest member of the royal family who wanted to follow protocol, the claimant sought advice from two senior members of the royal family on how best to address the situation".More news: NBA’s Raptors denied permission to play in Canada, head to Tampa
A trial was due to take place in January 2021, but this has now been postponed until autumn 2021, with the Duchess' legal team citing "confidential grounds" as the reason for a postponement. However, in a ruling earlier yesterday, the judge Mark Warby said Markle did not appear to be an important witness in the case and it was inaccurate to view it as a family battle.