Samantha Markle's book about Meghan is out in the US

Samantha Markle's tell-all about sister Meghan is out in the US and it's safe to say the Duchess of Sussex will be bracing for impact.

The book is called The Diary of Princess Pushy's Sister: A Memoir, Part One is expected to detail Samantha's criticisms of Meghan since the former Suits actress met Prince Harry and joined the royal family.

Chapters include 'Queen Would be Appalled' and 'Looking For Mr Right The Wrong Way'.

In the past Samantha has accused the duchess of mistreating their father Thomas Markle Snr and misrepresenting herself and her upbringing.

RELATED: Meghan left 'sick to her stomach' by Samantha Markle's tell-all memoir

The book is being published by Barnes and Noble however the company has not commented publicly about it's contents.

Meghan was starring in hit US TV show Suits when she met Prince Harry in London. The couple started dating and married on 19 May 2018.

It was ahead of the wedding that Meghan's strained relationship with her family became apparent. Her father participated in staged paparazzi photos showing him trying on a suits, arranged by Samantha.

Following the fallout Thomas suffered a heart attack and pulled out of the wedding, leaving Prince Charles to walk Meghan down the aisle.

RELATED: Where are Thomas and Samantha Markle now

In January a source told In Touch the Duchess felt "sick to her stomach" but planned to ignore it publicly.

A pre-release description of the book promises it will expose "hidden truths about her family" and detail how Meghan's "royal fairytale" went wrong, adding "the truth is stranger than fiction".

It also reads: "Samantha Markle finds herself caught in between the cross hairs of media mayhem, when she reveals hidden truths about her family."

While both Samantha and Thomas Markle gave numerous media interviews following their falling out with Meghan, Samantha has been focused on writing her book most recently.

Samantha did come forward to describe Harry and Meghan's resignation from the British royal family as a "slap in the face" for the Queen.

"Prince Harry and Meghan have quite a bit of apologising to do," she told Inside Edition at the time. "We aren't talking about teenagers, we are talking about adults who knew what they were doing and in regards to my father it was so incredibly wrong and shocking."

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She also accused Meghan of enjoying the attention of being a royal, adopting a "contrived British accent" since marrying into the monarchy and criticised her spending since becoming a duchess.

The only member of Meghan's family to have met her son Archie is her mother Doria Ragland. The Duke and Duchess of Sussex now live in California near Meghan's mother's home.