"She would be very proud of her sons and their wives," the Duchess of York tells People of Diana's two sons with Prince Charles. "If she were sitting with me right now, I know she would say, 'I am so proud of both of my boys and the wonderful wives they have chosen.' Because each has got her own voice."
Not only would Diana approve of her sons' choices, but Fergie also thinks she would love life as a grandmother of five. William and Kate have three children -- Prince George, 7, Princess Charlotte, 6, and Prince Louis, 3 -- and Harry and Meghan have two -- Archie, 2, and Lilibet, 1 month.
"She would be just like me, obsessed with her grandchildren. Because that's what she loved," the ex-wife of Prince Andrew shares.
Fergie and Andrew share daughters Princess Beatrice, who is mom to 5-month-old son August, and Princess Eugenie, who is expecting her first child.
According to the duchess, Diana "adored my girls. She adored the boys. This would be her haven. Her heaven."
The two had a longstanding friendship, with Fergie calling them "best friends" from the time Diana was 14 and she was 15.
"She taught me so much of public life," Fergie shares. "She was so brave. We used to have the most incredible time together."
Harry and William recently reunited in person for the unveiling of a statue in Diana's honor at the Sunken Gardens in Kensington Palace. Watch the clip below for more.