Now, Diana’s biographer Andrew Morton confirms to New Idea that the Princess of Wales was so desperate to have a daughter that she would mention it frequently to Prince Charles, even though their marriage was faltering.
“Diana wanted a baby girl. She used to tease Prince Charles, saying that, ‘Oh, wouldn’t it be nice if we had a baby girl.’ And this is especially when Fergie came around with Eugenie and Beatrice,” he reveals.
The two princes were always well aware of Diana’s desire for a daughter, which is thought to be one of the main reasons why they’re so keen to reconnect with Laura.
“William and Harry grew up knowing how much their mum wanted a daughter and would’ve loved to have had another baby – hopefully a little girl. So they always wanted a sister.
It was something they spoke about a lot when they were growing up, that they wished that their mum’s dream of having a daughter had come true,” shares the source.
Up until now, Laura, a mother-of-three, has lived away from the spotlight and hasn’t been close to her relatives, which is why not many know about the princes’ sibling, but Harry and William have found a new opportunity to rebuild the relationship with Laura, who is often called the ‘secret sister’.
Despite having joined the family back in 2005 when her mother married Prince Charles, very little is known about the former art gallery manager who is four years William’s senior.
“When their father married Camilla, Harry and William really tried to bond with Laura, but it was difficult. There was a lot of tension between the three of them because of Camilla and Charles’ affair for all those years.
So, while Harry and Wills wanted to be close to their new sister, it was difficult in those early years,” explains the source.
Unlike her step-siblings, Laura, whose biological brother is well-known food critic Tom Parker Bowles, has only ever attended a handful of official royal events.
She’s never publicly discussed her mother’s relationship with the future King of England, but according to brother Tom, the pair found it tough when the affair was made public.
“The paparazzi used to follow us everywhere and lurk around like spooks,” Tom told a UK newspaper.
“We used to keep binoculars in my mother's bathroom and one of us would look out every morning to see how many paparazzi were hiding in the bushes.” He added that the duo has always felt like outsiders.
“We are not part of the royal family, because we’re commoners, straight out commoners,” he revealed.
Camilla’s only daughter – Laura’s father is Andrew Parker Bowles – was last seen in public at Harry and Meghan’s wedding in May 2018.
She attended with her husband, also named Harry, a former Calvin Klein model turned chartered accountant.
It appears that, with the arrival of the now-3-month-old Archie, Laura has found it’s the perfect time to strengthen ties with her stepbrothers.
“Laura has three beautiful children herself and loves being a mother,” reveals a royal insider. “She’s really hoping to be able to have a relationship with Archie as she doesn’t have much of one with William and Catherine’s children.
Laura would love it if all the children played together and she knows her mother would love to see all her grandchildren under the one roof, too.”
While Laura may not have spent quality time with George, Charlotte and Louis over the years, her daughter Eliza, now 12, was flower girl at William and Kate’s wedding in 2011.
“William and Laura have obviously been a part of each other’s lives since they were children. They may not see each other often and they lead very different lives, but they have been through a lot together.”
The pair’s relationship hasn’t been without its difficulties. According to royal writer Katie Nicholl, William in particular struggled to get along with Laura during their younger years, after Prince Charles split from Diana.
“William and Laura used to have terrible fights over who was to blame for their broken homes,” Kate wrote in her 2010 book, William and Harry.
“William would blame Camilla for all the hurt she had caused his mother, which would send Laura into a rage.”
She added that Laura was very protective: “Laura was not having any of it. She would take a hard line and fire back at William: ‘Your father has ruined my life.’”
She also claims that it took Laura a long time to accept Prince Charles into her life.
“When Charles telephoned Camilla at the family home in Wiltshire, Laura would pick up an extension and shout down the receiver: ‘Why don’t you stop calling Mummy and leave our family alone.’
“She couldn’t care less that it was the Prince of Wales. She blamed him for breaking up her parents’ marriage and was not afraid to tell William so.”
Over the years, however, William and Laura found a mutual respect for one another. “When they stopped blaming one another’s parents and let go of their painful pasts, Laura and William got along well.”
Now, says the source, thanks to Archie, the siblings have found each other again and their relationship is set to go from strength to strength.
“They are talking more and more with each other. It’s going to take time, but Harry and William are loving reconnecting with their sister after all this time.”
For more, see this week's New Idea - out now!