Symone Salwan, 49, died just over 12 hours after being admitted by ambulance to Tunbridge Wells Hospital in Kent.
The mum-of-two had complained of four days of flu-like symptoms and pain in her hip and leg before being rushed to hospital.
Symone developed sepsis and sadly died on February 16, 2020, according to the family's lawyers.
Her grieving relatives have instructed medical negligence experts to investigate her care under Maidstone and Tunbridge Wells NHS Trust, which runs the hospital that Symone attended.
Symone, who had a son, Kishi, 11, and a daughter, Kaya, nine, was generally fit and healthy before her death, her family said.
She began feeling unwell with flu-like symptoms on around February 12, 2020. Two days later she fainted at home.
On February 16, Symone became confused. She was taken by ambulance to hospital arriving at around 5.30am.
She had a raised temperature, was vomiting and it was noted she hadn’t passed urine for several days.
Legal firm Irwin Mitchell, which is representing Symone's family, said that her condition deteriorated through the day and she was transferred to intensive care before she developed multiple organ failure and died at 10.45pm.
Symone's partner Graham Crabb, 56, said: “The last year or so and trying to come to terms with what happened has been incredibly difficult for all of us.
“Symone adored her family; she was a caring and amazing friend. She loved dancing, the outdoors, the sun, good wine, good chats and good laughs.
“She was also an incredible woman, a super-woman and devoted her time to making a real difference to the lives of older people.
“Her unexpected death has left a deep hole in all our hearts that will be difficult to heal."
Graham and Symone's brother Simon Salwan, 48, are campaigning to raise awareness of the signs of sepsis – which sees the body attack itself in response to an infection - and the importance of early treatment.
Sepsis symptoms include slurred speech, confusion, extreme shivering and muscle pain, passing no urine in a day, severe breathlessness and mottled or discoloured skin.
The family has also instructed Rachel Osborne, a medical negligence expert at legal firm Irwin Mitchell, to investigate the circumstances of Symone’s death.
Ms Osborne said: "Understandably, the family have many questions about the events that unfolded in the lead up to Symone’s sudden death.
“We’re now investigating the family’s concerns to provide them with the answers they deserve.
“In the meantime it’s vital that people are aware of the signs of sepsis, the importance of seeking urgent medical attention and how early diagnosis and treatment can make all the difference.”
Symone ran a business providing care and support to people in their own homes. The company won several awards and accolades, including at the 2017 Sevenoaks Community and Voluntary Awards.
She was also an avid fundraiser for national and local charities. She co-chaired the Sevenoaks Area Dementia Friendly Community, chaired the West Kent Dementia Action and was a trustee of the Carers Wellbeing Initiative.
Following her death Symone’s family continued to raise money for charities in her memory.