Smith, also known as Lucy, had two children - Megan, nine, and six-year-old George - and was looking forward to marrying her fiance Darren O'Neill. They had just bought a home in Billericay, Essex, when she died last year.
Her sister Caroline said: "Had Lucy initially been given that simple blood test and received the treatment that she needed on the Friday when she saw a GP I am convinced that the outcome would have been a positive one. Megan and George would still have their wonderful, beautiful mummy."
Her mother Shirley Smith, 76, said: "The doctor first gave her an antidepressant that is usually used to relax muscles when the patient has a trapped nerve.
"Her regular doctor wasn't the doctor who sent her to the physio, it was another clinical practitioner. The doctor did not take her blood pressure and that's something they should do automatically."
After visiting a physiotherapist on the doctor's advice, Smith was told "to come back in a week or two" because they could not treat her while she was in such obvious distress, her mother said.
Her daughter's second visit to a GP was at a different surgery. "That's when the doctor sent her to Basildon A&E," her mother said. It was at casualty that Smith had her blood tested and her blood pressure taken, leading hospital doctors to immediately put her on antibiotics and begin treating her for sepsis.
Mrs Smith, who with her other daughter has been helping Mr O'Neill care for the children, said: "Lucinda was a beautiful and brilliant young woman. She was such a vibrant character.
"George has asked questions at Easter like, 'If Jesus can come back, why can't my mum come back?' "
Sepsis is a potentially life-threatening condition triggered by an infection or, as in this case, an injury.
It causes the body's immune system to go into overdrive as it tries to fight an infection, which can reduce the blood supply to vital organs. Without prompt treatment, it can lead to multiple organ failure and death.
Smith first visited her GP on Friday, March 27, last year, a few days after spending time in the garden, when she scratched the back of her hand. But because she was experiencing pain in her shoulder, the cause of the pain was not immediately identified.
The doctor diagnosed a trapped nerve and prescribed anti-depressants to relax her and help her sleep.
She was also told to see a chiropractor, whom she visited that afternoon and was given acupuncture. Her family noted that even at that point she was vomiting and in pain.
Three days later, the following Monday, her fingers and arm had become red and swollen, she was still vomiting and in much worse pain.
She saw another GP who diagnosed a possible blood clot and told her to go to A&E.
Staff at Basildon Hospital's casualty department gave her a simple blood test straight away and 30 minutes later she was diagnosed with sepsis and put on intravenous antibiotics. After being admitted to a general ward for one night, she deteriorated and was moved to a critical care ward with an increased dose of antibiotics. The next day she was put on a ventilator.
She began to suffer organ failure and late that night she suffered cardiovascular, renal and respiratory failure and died.
An inquest said she died of toxic shock caused by sepsis.
HOW TO SPOT THE WARNING SIGNS
If a child or adult who has had any infection - even a mild cold - develops one or more of the following symptoms, call 111 immediately and say you think they have sepsis:
• Abnormally cold to the touch.
• Breathing rapidly or struggling for breath.
• Very lethargic or difficult to rouse.
• No urine (or wet nappy) for more than 12 hours.
• Skin mottled, blueish or extremely pale.
If sepsis is suspected by doctors, treatment with antibiotics must begin as soon as possible - ideally within an hour of diagnosis - even before blood tests have been carried out.
