Meghan Markle has revealed an adorable nickname that her two children have for her in a new post on Instagram. The Duchess of Sussex is celebrating Mother's Day in the US today, with the annual holiday marked on the second Sunday in May each year.

The 43-year-old referred to Prince Archie, 6, and Princess Lilibet, 3, as her "two gems" but also gave fans an insight into a sweet nickname that they have for her. Alongside a new picture of Meghan hugging both of her children, the doting mum shared that Archie and Lilibet call her "mama mountain" - suggesting that the youngsters love to show her affection.

As well as wishing her followers who also hold the title of mum a Happy Mother's Day, Meghan added: "And to these two gems - who still attempt to climb “mama mountain”, smother me with kisses, and make every day the most memorable adventure…. being your mom is the greatest privilege of my life", followed by a red heart emoji.

The Duke and Duchess of Sussex have largely made the decision to keep Archie and Lilibet, affectionately known as Lili, out of the spotlight.

Despite this decision, Meghan has treated fans to various pictures of Archie and Lilibet since her return to Instagram back in January.

The doting mum uploaded a new picture of Archie earlier this week to mark his sixth birthday on May 6. Alongside the picture of Archie, it didn't go unnoticed that Meghan just referred to her son with his name - leaving out his royal title of 'prince'.

The caption, accompanying the picture which showed Archie with his back to the camera, read: "Our son. Our sun. Happy 6th birthday to Archie! Thank you for all of the love, prayers, and warm wishes for our sweet boy. He’s six! Where did the time go?

"(And for all of you who came to celebrate with us at his party last weekend, thank you for making his birthday so incredibly special [love heart emoji])"

Meghan and Harry have lived in California for five years, with the pair having stepped away from royal duties in January 2020.

The couple now reside in Monetcito with Archie and Lilibet, who will celebrate her fourth birthday next month.