Zara is also in the Queen's good books, with sources saying that the pair are quite close.
Back in 2019, royal editor Ingrid Seward spoke of Her Majesty's relationship with Zara and her husband Mike Tindall, 42, claiming that the 94-year-old has a "tighter bond with them than she does with Kate and William".
Meanwhile, Princess Beatrice, 32, and Princess Eugenie, 30, daughters to the Queen's second and most scandalous son Prince Andrew, 60, are also said to have a special bond with the monarch.
It's even been rumoured that Eugenie is so close with her grandmother that she calls the 94-year-old "granny" in public, while her other grandchildren stick with the formal "the Queen".
Her Majesty also holds a soft spot for her youngest grandchildren.
Born to the monarch's youngest son, Prince Edward, 56, Lady Louise Windsor, 17, and James Viscount of Severn, 13, are rumoured to be tied with Peter as the monarch's favourites.
Back in 2019, a royal insider told The Sun that “the Queen loves the fact that Louise and James relish their time at Balmoral, and she has become particularly close to Louise, who seems to have become her favourite grandchild, closely followed by James".
It looks like Peter has some competition.
When it comes to Prince Charles', 72, sons, let's just say the Queen has her favourite.
Although Harry's decision to step back from his royal duties cast a wedge between himself and some of the other royals, the 36-year-old has maintained a close relationship with his grandmother.
Before leaving the firm, Harry was constantly photographed alongside the Queen, the pair laughing and joking together at royal events.
When the heir's youngest son decided to step away from his royal roots, the Queen was nothing but supportive as she expressed her love for Harry, along with his wife Meghan, 39, for their work over the years.
"Harry, Meghan and Archie will always be much loved members of my family," the Queen wrote in a statement, "I want to thank them for all their dedicated work across this country... and am particularly proud of how Meghan has so quickly become one of the family."
And so, we are left with the least favourite...
The grandchild who gets the least of Her Majesty's time, on a private level, is rumoured to be Prince William.
Because the 94-year-old has spent much of her life mentoring William, 38, for the day he will take the throne, the Duke of Cambridge has endured a much more serious relationship with his grandmother.
As a result, the closeness between the pair is reportedly missing, meaning the future King is favoured less than his brother and cousins.