Though they have hardly spent any time together over the last two years, a bond between Prince George, Princess Charlotte and Prince Louis, and cousins Archie and Lilibet, could be what truly reunites brothers William and Harry, according to a royal author.
Journalist Tina Brown, author of The Diana Chronicles, has suggested the link between the cousins could be crucial to a reconciliation for William and Harry, whose rift has now continued for some 18 months.
The Sussexes took Archie to Canada when he was just six months old, on their 'extended break', and he has not been back to the UK since. Lilibet, at a month old, has not met her British cousins.
"There are going to be these very cool American cousins, which I think is a great sub-plot for the whole house of Windsor," Tina said, speaking at a Telegraph event about the legacy of Princess Diana.
"George, Charlotte and Louis are probably going to be rather envious of the fun... you won't be able to keep them out of Montecito.
"It's probably going to be those children, those cousins that in the end bond them back together.
"There's nothing like having those young relationships. Harry for instance is very close to Eugenie and Bea, and whatever has happened in that horrendous strata of Andrew, the cousins are very very close, which speaks well for the future of this family.
"I think in the end they will develop an equilibrium between them.
"I think the key moment will be when the Queen dies because... at that point, a great solemnity will fall upon the younger generation, there will be the most enormous identity crisis for the country and the family will pull together.
"They will want to support their father, and William will find he has the whole Duchy of Cornwall to run and he is quickly in the running for succession. It will concentrate the minds of the children in that family."
'No talks' between William and Harry after brief reunion
Harry, 36, and William, 39, reunited briefly on 1 July in Kensington, as they unveiled the statue of their mother Diana on what would have been her 60th birthday.
They were pictured looking at ease with one another, with Harry relaxed and joking with the family members who were invited to the small ceremony.
But it was reported that Harry left just 20 minutes after the ceremony had finished, suggesting there was little time for reconciliatory chats with brother William.
Recently, former royal butler Paul Burrell said he would love to see the brothers patch up their speculated feud, and said it would be the perfect birthday present for the late Diana.
"I really hope that being back at Kensington Palace, their former home, with the statue of their mother, will bring it all home to William and Harry. They were once so close," he said.
"Kate is somewhat of a peacemaker, so I think her being there will be integral if there’s any hope of the boys reconciling. It would be the best of birthday gift to Diana if they were to make amends and move forward as a family rather than as enemies."
Speaking after the unveiling, Tina Brown, who interviewed Diana in the months before her death in 1997, noted that the brothers are different in personality, with Harry modelling himself on his mother, "who was about feeling, about following her heart, breaking free.
However, she warned: "But he may not have absorbed some of her other lessons."
She added that Diana would have been "enormously sorry" to see the rift between Harry and William and "would have spent a lot of time trying to reconcile the sons for every reason".
Additional reporting by Rebecca Taylor.
Never miss a thing. Sign up to Yahoo Lifestyle’s daily newsletter.
Or if you have a story idea, email us at email@example.com.