The Queen spent only 15 minutes with Prince Harry and Meghan Markle during the Platinum Jubilee, according to reports.
The Duke and Duchess of Sussex flew to the UK for the four-day celebrations with their three-year-old son Archie and daughter Lilibet, one.
But despite the Queen meeting her namesake great-granddaughter for the first time, their meeting was kept "formal" by Buckingham Palace aides and lasted only a quarter of an hour.
A source told the Sun : "It was a quick in and out job. It was all quite formal".
The couple are rebuilding relationships after making a series of explosive allegations on royal life.
Buckingham Palace has declined to comment on the claim.
During their fleeting visit to the UK, Harry, 37, and Meghan, 40, threw Lilibet a garden party at Frogmore Cottage to mark her turning one.
The Sussexes shared a picture of Lilibet smiling during the birthday picnic in a pale blue frock with a blow in her hair.
The following day, the couple flew back to their home in the US last Sunday an hour before senior royals appeared at the Platinum Jubilee pageant.
On Friday, Prince Harry, 37, was spotted in his first public outing since he and Meghan, 40, quietly left the UK.
He was spotted enjoying a game of polo in the Californian sun in Santa Barbara on Friday.
It comes as a royal expert claimed the rift between Harry and his brother Prince William had entered "a new rotten phase".
The pair were not pictured together throughout the Jubilee festivities, leading experts to believe their feud is ongoing.
Harry and Meghan made one public appearance during the four-days, at the service of thanksgiving for the Queen at St Paul's Cathedral.
They were also pictured watching Trooping the Colour from a window at Buckingham Palace, but were not part of the carriage procession or permitted onto the balcony with working royals.
During Trooping the Colour, William and Kate were not publicly spotted with Harry and Meghan.
"It's nearly a year since we last saw William and Harry together, and in that time the situation seems to have only deteriorated further," said Daniela Elser, and expert on the Windsors.
"By my best estimate the closest that Prince William and Prince Harry came to one another throughout the entirety of the Queen's Platinum Jubilee celebrations last week was around about five metres.
"What has come into clear focus is that this is not temporary iciness that a few conciliatory words and a brusque hug might fix. It is a state of deep permafrost with no end in sight."
