Jacintha Saldanha, 46, had answered the prank telephone call to London's King Edward VII hospital, which was treating Prince William's pregnant wife Catherine for morning sickness.
She had put the call from the station through to a colleague, who relayed details about Kate's condition which made headlines around the globe. Saldanha was later found dead in staff accommodation.
A member of her family, who live in the town of Shirve 400 kilometres (250 miles) from the southern city of Bangalore, said they could not believe the mother-of-two could commit suicide.
"We were shocked to hear from her husband (Benedict Barboza) that Jacintha was no more. He did not tell us that she committed suicide," Jacintha's sister-in-law Irene D'Souza told AFP by telephone.
"It is hard to believe Jacintha could commit suicide as she was not the type of woman to do it."
D'Souza said Jacintha was planning to come to India to celebrate Christmas with the family and they were planning a big party.
"But today we are going to the church to pray for her soul and for her children, who are going through a bad time."
The presenters at Sydney's 2Day FM radio posed as Queen Elizabeth II and William's father Prince Charles to obtain details of Catherine's condition.
British media have termed Saldanha's death a suspected suicide. Police, ahead of an autopsy next week, say it remains unexplained but is not being treated as suspicious.
William and Kate, who left the hospital last week, said they were "deeply saddened" by the death of the nurse.
Saldanha lived with her husband and two children in the western English city of Bristol. She had moved to Britain from India around 12 years ago.