Princess Eugenie to be invited to Balmoral Castle only if Prince Andrew joins

Princess Eugenie's attendance at a Royal Family gathering is uncertain following the release of a recent photo. 

The Princess of York, 34, shared a summer holiday snapshot over the weekend featuring her sons August, three, and Ernest, one. 

In the image, Eugenie is seen from behind, holding her children while walking along a bridge at a sandy beach. The photo, which includes a simple blue heart emoji, is thought to have been taken by Eugenie's husband, Jack Brooksbank.

While the location of the photo is unclear, Eugenie and Jack are known to divide their time between the UK and Portugal. Many fans speculated that the picture was taken at a holiday resort in Portugal. 

This news coincides with King Charles and Queen Camilla's summer stay at Balmoral Castle in Scotland. The Duke and Duchess of Edinburgh are anticipated to join the monarch, having been seen in Edinburgh over the weekend. 

Additionally, Princess Kate and Prince William are expected to bring their three children to the Aberdeenshire residence.

Princess Eugenie and her sister, Princess Beatrice, have visited Balmoral in previous years, but it remains uncertain whether they will attend this year.

A source told The Daily Beast that Princess Beatrice and Princess Eugenie will likely only be invited to Balmoral Castle if their father, Prince Andrew, is present.

However, the Duke of York, 64, is no longer a working royal and is currently engaged in critical discussions with King Charles about his residence at Royal Lodge. 

Despite not having arrived at Balmoral yet, Eugenie and her husband, Jack, seem to be enjoying their summer break, as evidenced by a recent Instagram post from the princess. Eugenie has previously expressed her fondness for the Scottish castle.

Speaking of the estate, and her late grandmother's fondness, the 34-year-old described it as the "most beautiful place on earth".

The mother of two previously explained on the 2016 ITV documentary, "Our Queen at Ninety", how much it meant to her late grandmother - and what the royals get up to there.

Eugenie said: "It's the most beautiful place on earth. I think Granny is the most happy there. I think she really, really loves the Highlands."

She added: "Walks, picnics, dogs – a lot of dogs, there's always dogs – and people coming in and out all the time.

"It's a lovely base for Granny and Grandpa, for us to come and see them up there; where you just have room to breathe and run."