The Duchess of Cambridge glowed with pride as she stood by the Queen's side while welcoming US President Donald Trump to Buckingham Palace last week. And royal insiders reveal there's a secret reason behind Kate's smile – she's about to be crowned Queen!
Clad in a white Alexander McQueen gown topped off with Princess Diana's favourite Lover's Knot tiara, Kate, 37, turned heads at a sumptuous banquet, as she and Prince William mingled alongside other senior royals.
It was also the perfect chance for Kate to debut her blue and gold sash, representing her appointment as a Dame Grand Cross of the Royal Victorian Order, a highly chivalrous award given by the Queen in gratitude for royal service.
"Everyone in attendance agreed Kate was utterly majestic and every inch the monarch-in-waiting," reveals a royal source. "There's no doubt Kate stole the show with her elegance and poise."
It's little wonder then that multiple sources confirm it's all but inevitable she and Prince William, 36, are poised to leapfrog the Duke and Duchess of Cornwall – with the Queen's blessing – as next in line to the throne.
"This comes after months, if not years, of grooming Kate to take over the crown, with her husband as her king," adds the insider. "Now it's finally happening and she can't quite believe it herself."
While Prince Charles, 70, is currently next in line to reign, when the Queen steps down or dies, it's now thought to be privately accepted Her Majesty would be open to bypassing her son and his wife Camilla, 71, in favour of grandson William and his wife of eight years, Kate.
"The Queen isn't the only one who wants Kate and William on those thrones – they're the public's first choice, too," notes our insider. "Charles must constantly feel like he's losing grip on his successorship, but it's actually been in the works for some time and it's likely he'll have no choice but to accept it."
Talk of who will succeed the Queen ramped up as she marked her 67th year as the reigning monarch, with Kate's loyalty and dedication to the royal family propelling her up the ranks.
"She's upped her dedication in the last few months and it's paid off," explains our source, who notes, "Kate and the Queen had their first solo royal engagement in March, something Kate has been patiently waiting for for eight long years."
WATCH: Queen Elizabeth and Kate Middleton step out for their first joint appearance. Post continues after video...
Sources say Kate has won Her Majesty over by proving her ability to keep her cool throughout ever-challenging instances – not least her mature approach towards her new sister-in-law the Duchess of Sussex, who has been mired in drama ever since her wedding to Prince Harry in May 2018.
"Once again Kate was the member of the household the Queen knew she could rely upon to represent the family," says our source.
Sadly, Kate's crowning moment will only amplify rumours of a deepening rift between the once close Sussexes and Cambridges.
"As Kate and William move towards securing their place as the head of the family, or at least in waiting, it seems resentment continues to build with the others," our source says.