Ms Ferguson's other publishers have remained tight-lipped when asked whether they plan to sever links with her.
Harper Collins, which has published two of her titles, the most recent being A Most Intriguing Lady which came out in 2023, previously declined to comment but pointed to the fact that both her books remain in print and available.
Mr Mountbatten-Windsor, and Ms Ferguson, are due to move out of his Windsor estate, Royal Lodge.
Mr Mountbatten-Windsor will move to the King's Sandringham estate in Norfolk. It is not yet clear where Ms Ferguson will go.
On Friday, the Daily Mail reported that she is preparing to move in with her daughter Princess Eugenie in her Portugal home, although there has been no official confirmation of this. Ms Ferguson's representatives declined to comment on these reports.
Ms Ferguson has also faced a separate scandal about her own links with Epstein.
In September, several charities dropped her as patron or ambassador after an email from 2011 revealed that she called Epstein her "supreme friend" and seemed to apologise for her public criticism of him.
Away from her philanthropic work, Ms Ferguson has various business ventures, and has written several children's books, non-fiction about Queen Victoria, and her own memoirs.