“Pippa has kept a diary of all the unbelievable moments in her family’s life since she could hold a pen,” says the insider.
“It’s been hard for Pippa to keep quiet and let her big sister face so much alone, despite having a lot to say on matters.
“Pippa is desperate to set the record straight and give her side to the story, but there’s one big hurdle she has to overcome – Kate.”
Friends say the princess, 41, has gently reminded her younger sister that tell-alls have not done well for the royal family in the past, with Spare particularly “traumatising” them.
And while Kate appreciates Pippa so much for wanting to fight in her corner via this book, she is nervous about how the memoir will be received.
However, ultimately she does trust Pippa.
For her part, Pippa is all too aware how things could end for her if she were to rock the boat in any way – and thus she has no plans to!
Indeed, our source stresses she has no desire to be “tarred with the same brush” as Prince Harry.
In fact, far from wanting to dish any dirt, Pippa wants to stick up for Kate, who has had to remain stoic and silent all this time.
“Pippa has a lot of things she wants corrected, but most of all she wants to show Kate and William how she sees them,” the insider adds.
Pippa has previously published two lifestyle books – the party-planning venture Celebrate, and the 2016 recipe book Heartfelt.
She’s reportedly wanted to write a memoir “for years”.
But the books keep coming. Pippa’s not the only one of Kate’s relations putting pen to paper – her controversial maternal uncle, Gary Goldsmith, is also penning his own bombshell tome!
According to reports, Carole Middleton’s younger brother has “already finished the first draft” of his memoir, which he hopes will give the Middleton’s an opportunity to “fight back” following Prince Harry’s claims in his own memoir Spare.
But, OK! magazine claims Carole, 68, has advised Gary, 58, to tone it down to avoid provoking the prince.
“They don’t want a book to fan the flames, which could set Harry off again,” a source told the publication.
“Carole has made it very clear that there should be no private family business written about.”
In 2020, Gary certainly didn’t mince his words when, in a LinkedIn post, he described Harry and his wife, Meghan Markle, as “two muppets” who are “craving attention”. Ouch!
“Initially, Gary said the book would not engage with any royal secrets that could potentially embarrass his niece or her husband,” another source told Tatler.
“Now, though, it appears he could have changed his mind. Still, he has promised that [Kate] and Carole will have the final say on the manuscript.”