'My first Mother's Day': Princess Eugenie shares new photo of baby son August

Princess Eugenie has shared a new photo of her baby son as she celebrates her first Mother's Day as a mum.

Eugenie posted the photo to her official Instagram page along with an image of her mother Sarah, Duchess of York, cradling her as a baby 30 years ago.

"I'm so excited to be August's mum and as you can see I'm enjoying my first Mother's Day," Princess Eugenie captioned the first image, of her son laying on a picnic blanket.

August is surrounded by yellow daffodils and is wearing a pair of white bunny slippers by Doudou et Compagnie, a French-made luxury children's brand that is also available in Australia.

He is wearing a pair of leggings featuring a whale-print from UK-based brand The English Beagle.

August is kept warm with a white knitted beanie and a matching cardigan.

The newest addition to the British royal family was born on February 9 at the Portland Hospital in London.

He is currently 11th in line to the throne but will drop back one place when Prince Harry and Meghan's daughter arrives in the coming months.

Princess Eugenie also paid tribute to her mother in her social media post.

"I'm also celebrating my beautiful Mumma with this picture of us from March 1990. You've taught me so much," she wrote.

"Happy Mother's Day to all."

Mother's Day in the UK falls on the fourth Sunday during Lent, while in Australia it will be celebrated on May 9.

And Princess Eugenie is not the only royal sharing special memories of their mothers on the day.

The Duke and Duchess of Cambridge revealed their children Prince George, seven, Princess Charlotte, five, and Prince Louise, two, write cards to their late grandmother Diana, Princess of Wales, every year.

The Cambridge children "make cards remembering their Granny, Diana, for William" the couple said.

Three cards were shared online, with Prince George writing "I love you very much and I think of you always" while Charlotte wrote, "Papa is missing you".

The cards were made public, Prince William and Kate said, because "for those experiencing bereavement, today may be particularly challenging".

Prince Harry's spokesperson has also confirmed the Duke of Sussex has arranged for a bouquet of flowers to be left at his mother's grave for the occasion.

The Duchess of Cambridge also revealed a cake her children had baked for her, which looked very similar to a Victoria sponge, and even shared a photo of her and her mother, Carole, from her childhood.

On the other social media pages belonging to the royals, Queen Elizabeth was pictured as a teenager with her mother, the Queen Mother, while Prince Charles shared a photo with the Queen from the Braemar Highland Games in 2010.

Camilla, the Duchess of Cornwall, was also pictured with her mother – Rosalind Shand – in 1990, four years before her passing.