Now, in a new interview on BBC's The One Show, Fergie gave further insight into her relationship with the royal.
Speaking to Michael Ball and Alex Jones, Sarah revealed she and Andrew share the same mantra for life.
'The thing about Andrew and I is that we go with our hearts,' she said.
'We go with the family unity. It’s about seeing the light in life.'
The duchess also sweetly described a practical joke she and Andrew played on the pair's future son-in-law, Jack Brooksbank.
Jack, who is set to marry the couple's youngest daughter Princess Eugenie in October, shares the same name as the family dog.
Fergie said, 'This is where Andrew’s brilliant, you see, because he says ‘Jaccck get off that chair!’
'Jack, son-in-law Jack, jumps up and says ‘Argh what have I done now’. Then we all said ‘No, not that Jack!’'
Recently, Fergie was spotted leaving a popular private nightclub in London's Mayfair.
The duchess sported a simple black dress paired with a bright pink jacket. She also wore colourful loafers.
Lou Lou's club in Mayfair is one of the most exclusive private members' club around the world. It sits behind an unmarked maroon door and royals, billionaires, and A-listers are all known to frequent it.