Speaking to Christine Lampard on ITV's Lorraine on Tuesday, the author was asked how difficult the past year has been during the pandemic.
Sarah said: "The pandemic has been extraordinary for everybody, it's been so challenging. But I think Prince Andrew is such a good man, he's a thoroughly good man, he’s a very gentle man, he's a really good father."
WATCH: Sarah Ferguson reveals what Prince Andrew is like as a grandfather
They became grandparents for the first time in February, with the birth of Princess Eugenie and Jack Brooksbank's son, August.
Princess Beatrice and her husband, Edoardo Mapelli Mozzi, are also expecting their first child this autumn.
Sarah appeared on Lorraine with Mills & Boon author Marguerite Kaye
Sarah said of her and Andrew's relationship: "We did co-parent very well, hence the reason why the girls are very solid and [have their] feet on the ground. But now, as a grandfather, he's really good. He can go for hours talking about football and all those sorts of things. And I'm like, 'Ok, off you go.'
"It's a joy to see him really shine as a grandfather. I think it's very important, family unity - communicate, compromise, compassion. Those are the three Cs that are essential… Life is about yourself and being able to have team spirit. Say what you feel - communicate, compromise and then compassion, let's go forward."
Her Heart for a Compass by Sarah Ferguson, Duchess of York, £11.99, Amazon
In an exclusive interview with HELLO! magazine this week, Sarah said of her five-month-old grandson: "Well, baby August is phenomenal. He's a very strong little chap. August thinks I'm hysterical. And it's so funny when I look at him because I make him laugh, and he goes all shy and flirts with me. Just shows you: boys. Boys!
"You know, he's just so, so cool but really, I'm very proud of Eugenie – and Jack [Brooksbank] because they're very good parents and, as any new young parents out there know, it's very challenging, isn't it? And they worry so much about the night duty and getting it right, and are they good enough? And are they getting it right? And Eugenie is really a great mother so I'm very proud of her.
Eugenie and Jack with baby August
"But ultimately, I say: 'You've done so well, just keep your confidence.' Mothering is intuitive, so you don't need to be told: you'll know."
Her Heart For A Compass is an immersive, romantic historical saga that Sarah co-wrote during the last lockdown with Mills & Boon author Marguerite Kaye. It was released on 3 August and tells the tale of Lady Margaret Montagu Douglas Scott, who was inspired by Sarah's great-great-aunt.
Lorraine airs weekdays at 9am on ITV and ITV Hub
HELLO!'s selection is editorial and independently chosen – we only feature items our editors love and approve of. HELLO! may collect a share of sales or other compensation from the links on this page. To find out more visit our FAQ page.
Make sure you never miss a ROYAL story! Sign up to our newsletter to get all of our celebrity, royal and lifestyle news delivered directly to your inbox.