The Duchess of York joined hosts Holly Willoughby and Joel Dommett on the This Morning sofa on Thursday, where she made a comment about Prince Harry's memoir, Spare.
Sarah Ferguson, 63, appeared on the ITV daytime programme to talk about her new historical romance novel, A Most Intriguing Lady, telling the presenters that she thinks it could knock Harry's book off of the Sunday Times Bestseller List. Watch the clip below to see what she said.
When asked by Holly if she thought her new novel could replace the Prince's memoir in the general hardback chart, she responded: "Well, I think so.
"I think Jeffrey Archer too," she jokingly added, prompting a laugh from Holly, who responded: "Take them all out!"
Sarah went on to say: "I think the most important thing is here I am, you've got to stay positive. There's too much unkindness. Social media is a sewer and cyberbullying has got to go."
This isn't the first time Sarah has publicly spoken about Prince Harry in recent weeks. When asked what advice she would give to Prince Harry, Meghan Markle and the Prince and Princess of Wales while speaking at an event promoting her new novel, the royal replied: "I think the best way to answer that is to really take hold and lead by example. I wouldn't give advice, I would say that your actions speak louder than words.
MORE: Sarah Ferguson makes 'terrifying' confession about adopting Queen's corgis with Prince Andrew
MORE: Sarah Ferguson shows off previously unseen corner of home with Prince Andrew
"[Princess] Diana and I, we played a lot and had a great time. I feel like she would be absolutely, and so is the King, so proud of their grandchildren and the family… I think forgiveness is key."
In a separate interview with People, she said that she has "no judgement" towards the Duke and Duchess of Sussex for deciding to step down as senior royals in 2020. "I don't believe that any single person has the right to judge another person," she said. "I'm not in a position myself to make any judgments. I have been judged all my life, and I have no judgment on the Sussexes."
Make sure you never miss a royal story! Sign up to The Royal Explainer newsletter to receive your weekly dose of royal features and other exclusive content straight to your inbox.