The source continued: "At the drinks before the dinner, a small group were talking to the monarch and she explained that Harry meeting Meghan had become a complete catastrophe and described her as 'evil'.
"It was clear that the Queen's health was failing and she didn't have long left; she appeared to be filled with regret over how things had turned out."
Meghan and Harry stepped away from royal duties in early 2020, and moved to the US shortly along with their now-six-year-old son Prince Archie.
Shortly after their decision become public, the late Queen released a statement which said that Harry, Meghan and Archie would remain "valued members" of her family.
Back in 2020, the late Queen shared: "Today my family had very constructive discussions on the future of my grandson and his family. My family and I are entirely supportive of Harry and Meghan's desire to create a new life as a young family."
The couple now reside in California with Archie and their daughter Lilibet, who was born in June 2021.
Harry and Meghan celebrated their son's sixth birthday earlier this week, and will mark Lilibet's fourth birthday in a few weeks time.