Princess Diana's friend posts candid photo on the 21st anniversary of her death

Princess Diana died 21 years ago. Photo / Getty Images

One of Princess Diana's friends has shared a rare glimpse of the princess living life away from the spotlight.

On the 21st anniversary of her friend Diana's death, Rosa Monckton shared the candid photo on Twitter.

"Diana as I remember her. Not enough is written about her sense of fun and zest for life. Friend and wonderful godmother to Domenica. RIP," she tweeted, alongside a photo of a laughing Diana donning sweatpants on what appears to be a plane.

Diana as I remember her. Not enough is written about her sense of fun and zest for life. Friend and wonderful godmother to Domenica. RIP pic.twitter.com/WP49dNDeEu

— Rosa Monckton (@MoncktonR) August 31, 2018

Monckton named the princess godmother of her daughter, Domenica, who was born with Down Syndrome and says Diana always believed in Domenica and her strength.

"She said, 'You just have to believe in her,'" Monckton recalled Diana telling her after Domenica's birth in 1995, according to People.

"She said, 'Believe in her, love her and I'll be there every step of the way.' She already had that vision of what Domenica could become, which I simply couldn't see."

Monckton says Diana would go with her to doctor's appointments and was always there for her.

She credits the princess as the inspiration behind her charity, Team Domenica, an institution that helps children with special needs and learning disabilities.

"Domenica was Princess Diana's last godchild, and Rosa passionately promotes the late Princess's belief that 'everybody needs to be valued and everyone has the potential to give something back,'" the charity states on its website.