Neighbour and close family friend Des Gilmore has helped Ms Sen's parents and sister organise the funeral that they are unable to travel to New Zealand for.
"We are all hanging in there, put it that way," he said. "I am not looking forward to tomorrow but we just have to let her rest in peace now, it's been a very difficult time for everybody."
A eulogy written by her grandparents will be read and flowers chosen by them displayed, said Mr Gilmore.
"They would have loved to come over, but they were unable to afford it sadly."
A private cremation will follow the service.
Detective Inspector Hayden Mander said the results of the original post-mortem examination were inconclusive and subsequent tests have not provided any clear answers.
He said the death had been referred to the coroner, but the investigation was ongoing to determine whether it is suspicious or not.
