Princess Eugenie and Queen Elizabeth II
Princess Eugenie and Queen Elizabeth II are very close. Pictured: Princess Eugenie and Queen Elizabeth II accept flowers from children outside Sandringham Church after the traditional Christmas Day service at Sandringham on Dec. 25, 2011 in King's Lynn, England Getty Images/Chris Jackson

Princess Eugenie and her grandmother, Queen Elizabeth II, seem to be very close with each other.

The Queen has a number of grandchildren, but she is particularly close to the next royal bride. Marcia Moody, a journalist for Town and Country, recently revealed that even if Princess Eugenie is not a working royal, she and her sister, Princess Beatrice, regularly attend functions with Her Majesty.

For instance, Princess Eugenie accompanied the Queen to the Easter Day church service in Windsor, the Royal Windsor Horse Show and the Royal Ascot. In addition, their closeness is evident in the way Prince Andrew's daughter calls the monarch in public.

Prince William and Prince Harry tend to err on the side of formality by referring to their grandmother as "The Queen." However, Princess Eugenie has more than once called Queen Elizabeth II "Granny."

In addition, Princess Eugenie is a regular visitor at the Queen's Scottish estate Balmoral. In ITV's documentary titled "Our Queen at Ninety," she explained why Queen Elizabeth II loves to stay there.

"It's the most beautiful place on Earth," Princess Eugenie explained. "I think Granny is the most happy there, I think she really, really loves the Highlands... Walks, picnics, dogs—a lot of dogs, there's always dogs!—and people coming in and out all the time. Family-wise we're all there, so it's a lovely base for Granny and Grandpa to be—for us to come and see them up there, where you just have room to breathe and run."

Princess Eugenie's mom, Sarah Ferguson, is expected to join the royal fold on her wedding day. Prince Philip has reportedly not yet forgiven Ferguson for her toegate scandal, which many believe caused her split from the Duke of York. But recent reports suggest that the Duke of Edinburgh and Duchess of York are willing to "bury the hatchet" for her.

Unlike Prince Philip, the Queen and Ferguson have already reconciled. In fact, they were seen chatting during Royal Ascot. Her Majesty was also present at Princess Beatrice's birthday and was reportedly impressed on the way Ferguson brought up her daughters.

"Her Majesty thinks Sarah has raised two lovely daughters and is very fond of both of them and looking forward to Eugenie's wedding, which they obviously chatted about at the party," an insider said. "The Queen always tries to see the best in people and she has stayed in close touch, even having tea with her regularly at Windsor."