Pals of the Duchess of Sussex, 37, said she was deeply upset because she felt she was being "taken advantage of" by estranged Samantha Markle.
A working title for the book was The Diary of Princess Pushy's Sister, 54-year-old Samantha revealed in 2016.
And earlier this month, she announced a possible second book she is working on – which is set to be called In The Shadows Of The Duchess.
The publication of the first book has been slated for April – around the time that pregnant Meghan is due to give birth to her and Prince Harry's child.
According to Samantha, the tome will "cover everything from behind the scenes that the world does not know about", she told the Daily Star.
She stopped reading things after finding out about her sister's book. She cried when she found out about it
But embattled Meghan – whose ties to her American family have come under intense strain since marrying Harry – is said to have been devastated by Samantha writing about her.
The Duchess now refuses to read any articles featuring her relatives – and tries not to look at any gossip about herself.
A friend told DailyMail.com: "She stopped reading things after finding out about her sister's book.
"She cried when she found out about it.
"Out of everything that's been said, the one thing that really upset her was that [the book].
"She and Samantha never had a very good relationship and she feels her sister is using her position for profit."
FAMILY STRAIN
It is believed that Meghan has not seen her half-sister – who lives in Ocala, Florida – since 2008.
But Samantha has regularly spoken out about her royal relation – slamming her for not keeping in contact with their dad Thomas.
Thomas Markle Snr, 74, was cut off by Meghan since he was exposed posing for stage paparazzi shots ahead of the royal wedding last May.
The Sun reported that Thomas later sent a heartfelt letter to his youngest daughter – but also suggested they should pose together for photographs.
The Duchess of Sussex decided she couldn’t continue speaking to her dad because of his media request.
It dashed Meghan’s hopes of a private reunion and now she is braced for another tell-all interview from Thomas.
DAD'S 'LIFE MISSION'
Meanwhile, his son Thomas Junior – Meghan’s half-brother – has revealed it is his father’s “life mission” to reunite with the royal.
Speaking from his home in Oregon, glassware-maker Thomas said: “My father is very hurt and very confused about what happened to the relationship with his daughter.
“And I think he is very frustrated now because he has a grandchild coming up with the favourite person that he worshipped."
But friends of Meghan say it's her that has been rebuffed by her dad.
An insider said: "It's not fair what he's done.
"He's always known how to get in touch with her and they've never been as close as he's made out."
Source: Read Full Article