A man was also found critically injured and remains in hospital.
Police have said the death is being treated as a homicide, and a visible police presence has remained in the Crichton area while inquiries continue.
Police have previously indicated there is no ongoing risk to the wider public.
A death notice published this week in the Otago Daily Times said Clark was “tragically taken”.
She was the daughter of the late Jasper Clark and Joan Clark, and a sister and sister-in-law to extended family across South Otago.
Her death comes just days after Clark delivered the eulogy at her father’s funeral, following the death of Jasper Clark on January 11.
Former colleagues described Clark as a highly respected and much-loved veterinarian with deep connections to the farming community.
John Smart, who worked with Clark for about 30 years across Clutha Vets practices, said her death was “a hell of a shock”.
“She was a highly respected vet,” he said. “I know the whole community down there will be absolutely in mourning for the tragedy of losing Jillian.”
Another former colleague, Tony Smith, described Clark as “an amazing person” who was deeply connected to her local area and the farming community she served.
Funeral arrangements have not yet been announced.
Ben Tomsett is a multimedia journalist based in Dunedin. He joined the Herald in 2023.