The photo with Diana show the pair smiling and looking out into the distance, while another snap includes a black and white picture of her two much-loved daughters, Eugenie and Beatrice.
Fans were quick to praise her post, with one writing, “You are truly an amazing woman yourself you are strong and beautiful and have a wonderful family. Thank you for remembering Diana”.
Another fan wrote: “Lovely photos! Thanks for honoring Diana! You and your daughters are wonderful women! Happy International Women’s Day!” added another.
The 59-year-old recently penned a letter saying 'enough is enough' with the online trolls pitting Meghan Markle and Kate Middleton against each other, saying it echoes how she and Princess Diana were untruthfully painted as 'rivals'.
The scathing letter comes amid frequent reports that Kensington Palace staff have had to a combat a steady stream of vile sexist and racist comments directed and Kate and Meghan online.
Fergie wrote in Hello! magazine: "We need to pay more attention than ever to what we're all being exposed to online. It's time to confront head on the fact that much of social media has become a sewer.
"I'm on Twitter and Instagram, and I'm grateful for the fact that they allow me to communicate directly with people who are interested, promote my charitable causes and let people read my own words rather than someone else's slant on them.
"But the truth is, a lot about these sites terrifies me. I rarely if ever go 'below the line' on social media or news websites and read people's comments."