In an interview with the Telegraph, the Duchess of York said she felt like she was being strong for everyone during a difficult time.
She said the death of Queen Elizabeth had left a hole in how much her ex-husband was supported by the royals: "When Andrew went through a hard time, I used to be able to throw it to The Boss," she said.
Ferguson also indicated that she disagreed with some of the criticism aimed at Andrew by the public in recent years: "Perception is so important. I see what that perception has done to a very kind man. I really mean that."
She told the paper she would always be there for Andrew because of the love she felt for the Queen.
The Duke of York has crashed out of public favour and has become sidelined by the Royal Family in recent years.
He has been subject to fierce criticism for his relationship with paedophile Jeffrey Epstein and sex trafficker Ghislaine Maxwell.
Last year he settled a lawsuit with Virginia Giuffre - a woman he claimed never to have met - after she accused the prince of having sex with her when she was 17 after she had been trafficked by Epstein.
The settlement was reportedly worth more than $10m.
The Duke of York has always denied any wrongdoing.
After being out of the public eye for years there have been several rumours he is considering pushing for a return. However, the King has made clear in recent years his intention to significantly slim down the Royal Family.
Whether Andrew heeds this remains to be seen - it was reported last month that he was exploring legal options to clear his name from Giuffre's accusations.
It has also been reported that the Prince may struggle in the near future to afford to maintain his Grade II-listed Royal Lodge, which sits near Windsor Castle, and has told to downsize his living arrangements.
This week, it emerged he had been offered the keys to the Duke and Duchess of Sussexes' Frogmore Cottage residence, but Andrew is believed to be reluctant to leave his home and where he often spends time with Ferguson.
In his Yahoo column this week, Omid Scobie – Yahoo UK's executive royal editor – pointed out that despite the rent on Royal Lodge being a pretty meagre £250 per week, the upkeep of the 30-room mansion is a far more significant at around £400,000 per year.
Andrew’s allowance from the Duchy of Lancaster – £249,000 per year – is coming to an end this April, accelerating his need to slim down his finances.