Samantha is the oldest daughter of Thomas Markle, and Meghan has not seen her since 2008. In 2018, Samantha was turned away from Kensington Palace after she arrived unannounced to visit her sister.
Like her father and half-brother, Thomas Markle Jr., Samantha is no stranger to publicly criticizing her sister. Samantha has previously branded Meghan as "a shallow social climber" with "a soft spot for gingers." She has also accused Meghan of abandoning their father.
Last year, Samantha told the The Sun that Meghan was "ripping through the Royal Family like a tornado" and "using" them for fame and fortune."
Even though Meghan asserts that her half-sister hardly knows her and said the claims are "absurd," the Duchess reportedly broke down in tears when she heard about the book.
The 330-page memoir will reveal the "hidden truths about her family, as a royal fairy tale plummets from the tea towels."
The book has been in the works for four years now and was initially just titled The Diary of Princess Pushy’s Sister, but the addition of "Part 1" suggests that Samantha has a lot more on her mind. It's unclear how many follow-ups there will be.
Meghan's in-laws might not "be unhappy" with the book, according to Samantha. "There is something in it for everyone. It has been an interesting journey," she told The Sun.
"It deals with my life and my perspective on several issues in the road as they intersect with this royal event in history," she continued.
"How that affects us as people and how the world reacted and what it really meant to us as a family. There was a lot going on behind closed doors that the world didn’t know," she said.
Although the memoir has been branded as a tell-all, Samantha rejects that title. "I wrote it respectfully knowing they [the Royal Family] would see it."
However, Samantha has not discussed the book with her sister and does not know how to contact her anymore but said that anyone who has nothing to hide shouldn't be worried when the book is released.
"Meghan will be in there. I don’t know if she will be comfortable with it. Some things she will and some things she won’t. It’s fair and balanced. Naturally, some things she will like and some things she won’t," she said.
"Truth is stranger than fiction and I have predicated myself on the truth," she added.
Samantha’s book comes months after the biography Finding Freedom was released, which Markle and Prince Harry have been accused of being involved with.