Meghan’s half-sister, Samantha Markle, 56, also says the book may make the duchess, 39, a bit ‘uncomfortable’.
Samantha’s book, The Diary of Princess Pushy’s Sister Part 1, is released nationwide in America on Friday.
She claims it will lift the lid on her relationship with Meghan, and reveal many family secrets.
Samantha told The Sun on Sunday: “I think the Royal Family will like it and will enjoy it and nothing they should be uncomfortable with. I hope they find it warm, funny, honest and heartfelt.”
She added: “I don’t know if she [Meghan] will be comfortable with it.”
The book is 330 pages and she says it will also detail how Meghan’s marriage into the British Royal Family affected the rest of her family.
How are Meghan and Samantha Markle related?
Samantha and Meghan share the same father, Thomas Markle.
Samantha also has a brother, Thomas Markle Jr, 55, who is Meghan’s half-brother.
None of Meghan’s family from her father’s side attended her 2018 wedding to Prince Harry.
It is believed her only family member in attendance was her mother, Doria Ragland.
Samantha is not believed to have ever been particularly close with Meghan.
And they have reportedly not been in contact for many years now.
Wheelchair-bound Samantha is a mum-of-three, and has repeatedly hit out at Meghan in the press, particularly regarding how poorly she believes Meghan has treated their father, Thomas.
Thomas, now 76, was set to attend Meghan and Harry’s wedding.
However, he claims they fell out when he appeared in a series of staged paparazzi photos.
Shortly before their wedding, he also suffered a series of heart attacks.
What else has Samantha said?
Appearing on Good Morning Britain in 2018, Samantha said she wished Meghan would get back in touch with their father – if only for the sake of gaining closure on their apparent feud.
She told the GMB presenters: “It is so critical and unfair that if there’s a misunderstanding she needs clarify because life is very short.
“He’s 74 and I feel if something happened to him and he passed away none of us could live with the fact he died unhappy and there was no closure. I believe she would want that also.”
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