Karen Pooley, from Lydney, travelled with a friend to Sal on 7 October for a fortnight’s holiday costing £3,000 and booked through Tui, the law firm said.
The retired mother-of-two became sick on 11 October with gastric symptoms including diarrhoea, and the next day she slipped on water leaking from a fridge while going to the bathroom.
She was transferred to a local clinic and over the next four days she continued to experience diarrhoea and vomiting along with severe pain from her fractured femur.
She was airlifted north-east to Tenerife in the Canary Islands for urgent care on 16 October and died in the early hours of the next day, lawyers said.
Her husband Andy, 62, said: “We’re utterly heartbroken.”
He said his wife appeared to be in “significant distress” when the family video-called her from home, and claimed communication from the clinic and their holiday provider was poor.
“We’re devastated and struggling to understand how she went on holiday and never came home,” he said.
Irwin Mitchell said Pooley’s initial death certificate, issued by the Cape Verde authorities, said she died of multi-organ failure, sepsis, cardio-respiratory arrest and a broken left leg.
The law firm has not given further details of the 56-year-old man who has died.