Louise Doherty, 41, passed away just days after developing the infection, which is normally associated with children.
The call centre manager from Greenock was rushed to Inverclyde Royal Hospital after developing serious breathing difficulties. She was transferred to a special intensive care unit there.
But after days in the special ward, she suffered a blood clot and lost her fight for life.
Her death, on 11 February, surprised doctors, who described the case as highly unusual.
Dr Peter Semple, a consultant at Inverclyde Royal, described it as a sad but isolated case. He said: "Chickenpox can be very unpleasant in adults, but is not usually life-threatening. It is very rare for chickenpox to be fatal.
"I have never known anyone to die from the infection in my 27-year career."
Miss Doherty's mother, Agnes, said the family were devastated and were trying to understand how the disease could have proved fatal. She said of her daughter: "Even though she was very ill, she kept her sense of humour."
Her sister, Linda McAlonan, added: "We are devastated. We are a very close family, and Louise and I were like twins.
"Louise lit up a room, when she walked in and lived life to the full. She was always out and about. She had a beautiful singing voice."
The funeral for Ms Doherty, who worked for IBM and lived with her mother, was held last week at St Andrew's Church, Greenock, where friends and family celebrated her life.
Chickenpox is caused by the varicella-zoster virus. The immune system makes antibodies during the infection.
These fight the virus and then provide lifelong immunity. Therefore, it is rare to have more than one bout of the illness. Most people have chickenpox during childhood and about 90 per cent of people will have had it by the age of 15. It is rare for adults to contract chickenpox.
It begins with a high fever, aches and headache, followed by a rash with itchy spots, and the symptoms are mostly more severe in adults.
Dr Jim McMenamin, a consultant epidemiologist at Health Protection Scotland, said yesterday: "It is mainly a childhood illness, but adults can be affected.
"It tends to be the quirk that if people escape chickenpox as a child, they are more likely to suffer complications as an adult."