She Broke Fashion Rules
For her first official royal appearance alongside Prince Charles, she wore a strapless gown, which was absolutely not a part of the dress code. She did this on multiple occasions: she once wore a choker as a tiara and wore dresses and skirts that showed her knees.
She Was Open About Her Marriage Troubles
Diana was one of the rare royals who was open about her personal life. She also talked about Charle's very public affair with Camilla Parker-Bowles. She has been quoted as saying "A woman's instinct is a very good one; obviously I had knowledge of it from people who minded and cared about our marriage ... There were three of us in this marriage, so it was a bit crowded." She wasn’t afraid to speak truthfully, making jabs at her husband.