Princess Kate's baby nephew, Inigo Middleton, made a rare appearance after his father and the royal's brother, James Middleton, shared a new photo on social media to mark Mother's Day on Sunday. The 37-year-old, who is regularly active on social media, posted a new snap of his wife, Alizée Thevenet and his one-year-old son on his personal Instagram account.

Alizée can be seen casually dressed and sweetly carrying her son, while Inigo, who looks adorable in a knitted jumper, a shirt, a pair of jeans and brown baby trainers, is seen holding onto his mother while looking away against a sunny backdrop. James accompanied the sweet snap with a caption: "Happy Mothers [Day] to all the amazing Mothers but an extra bit of love for this one [heart and flower emojis]". Fans flocked to the comment section to wish them well, with one saying: "Aw Inigo has grown so much. happy Mother's Day to Alizée, Catherine, Carole, Pippa and everyone else celebrating it today."

Another person added: "Happy mother’s day to Alizée! You’re a wonderful family."

A third user said: "So beautiful and precious. happy Mother’s Day to your beautiful wife, your beautiful Mummy and your beautiful sisters.".

A fourth one wrote: "Oh my god, Inigo has grown so much. Happy mother's day!"

Meanwhile, James's sister, the Princess of Wales, marked Mother's Day in her own way as she posted a video featuring shots of her and William in Norfolk last summer and said nature has been her family's "sanctuary" over the past year.

Last March, the future Queen announced that she had been diagnosed with a type of cancer, however, following a course of treatment over the last year, in January said she is now in remission.

Kate's video included scenes of some of the UK's most striking natural environments, from woodlands and fields to beaches and the ocean.

In the accompanying message, signed 'C', Kate wrote: "Over the past year, nature has been our sanctuary.

"This Mother's Day, let us celebrate Mother Nature and recognise how our bond with the natural world can help not only nurture our inner selves, but remind us too of the role we play within the rich tapestry of life."