For it was Catherine's book Black Diamonds - the very human story of the Earls Fitzwilliam, owners of the Grade I-listed country house near Rotherham until the 1980s - which first drew wider public attention to the mansion and the tragedies it witnessed.
Published in 2008, the book was a commercial success and many visitors to the house since it was saved for the nation in 2017 have read and been inspired by it.
Now Catherine has collaborated with the Wentworth Woodhouse Preservation Trust to launch a new tour based on Black Diamonds which promises access to areas of the house and grounds not previously seen by the public.
She has been heavily involved in compiling the itinerary, which will take in the rooms inhabitated by the Fitzwilliam family, their servants and later owners the Newbolds.
The private apartments in the West Wing, the kitchens, the Piazza Court and the bakehouse are all featured on the 90-minute guided tour, the first of which was led by Catherine last week before the general launch on October 6.
Visitors will hear stories about the Fitzwilliams' famous weekend parties in the house's late Victorian heyday and the incredible behind-the-scenes operation that ensured the house ran smoothly on a daily basis.
"The tour is really exciting, and a chance to bring history to life," said Catherine, who first saw the then-neglected and decaying Wentworth when she visited the estate while working as a TV researcher in 1999.
"It's very much my own itinerary, there are some rooms we can't get access to for safety reasons, but we will be taking people into areas that conjure up how life once was. It's not just telling the story of how the house came to look as it does now, it's about understanding the calamities that took place here in the 20th century."
Visitors will be able to view the Duchess of Kent rooms where the sixth Earl died in 1902. He was the patriarch responsible for vastly increasing the family's wealth by sinking coal mines on land he owned on the lucrative Barnsley seam.
"There's a toilet that was built for him in 1900 and was the only one in the house at the time - there was no running water then, so the footman would have to flush it for him. The Piazza Court had areas where the parlourmaids slept above it. It's a completely different tour to the others as it's not about politics or architecture, it's about how life was lived."
During her visit north, London-based Catherine will also be giving a talk about her book and there is also an evening with her research partner Martyn Johnson, a miner's son and former Wentworth village policeman whose contacts proved invaluable during the writing process.
"Martyn was brilliant, his knowledge of the area is incredible. He was my guide, and he took me to places I wouldn't have been able to get to and introduced me to people I wouldn't have otherwise been able to speak to. He found locals whose memories stretched back to the Fitzwilliams' time."
Since the Wentworth Woodhouse Preservation Trust took over the house and began an ambitious restoration programme, Catherine is hoping that her research - now 13 years old - may be updated by new papers collected by archivist David Allott, who has made numerous new discoveries about the estate's history.
"I'm hoping to meet David and look at all the new material. Something new could come to light."
She has also mooted the idea of a sequel to Black Diamonds, which ended in the immediate post-war period, when the family rented out their ancestral seat to a ladies' PE college and faced bleak prospects with a lack of male heirs and open-cast coal mining taking place in the grounds on government orders.
"The story of what happened between the mid-1950s and the present day is an interesting one. Maybe one day!
"I was thrilled when the Trust took on the house for the nation - it has a future now."
Black Diamonds tours cost £25 per person and run from October 6. Places must be pre-booked online.