THE father of murder victim Rachel O'Reilly has spoken of his devastation at losing a second daughter prematurely, but believes his two daughters have been reunited in heaven.

Ann Callaly, sister of murder victim Rachel O'Reilly, died on Friday morning after a two-and-a-half-year battle with cancer. Her father Jim Callaly was yesterday preparing to bury his daughters side by side.

Callaly said the family was trying to come to terms with the latest tragedy and paid a moving tribute to his daughter.

"We are absolutely devastated. She put up a great battle, a great struggle. She really thought she could beat it," he told the Sunday Tribune. "She was a wonderful daughter and a wonderful woman. She is with Rachel now. She will be buried beside Rachel. We have had a steady stream of visitors. This is a very difficult time for the family but we're all very close."

Ann Callaly (32) died at the family home in Whitehall, Dublin, at 5am on Friday morning surrounded by her family. Her funeral mass is due to take place tomorrow morning at 10am at the Church of the Holy Child in Whitehall. She will then be laid to rest at Balgriffin cemetery.

Ann's death comes just a fortnight before the sixth anniversary of her sister's murder. Rachel's husband Joe O'Reilly is serving a life sentence for the murder of his wife. His trial in 2007, was one of the most high-profile Irish criminal cases in recent history. Ann attended every day of the trial and was a source of great support for her parents Jim and Rose as well as her brothers Paul, Tony and Declan.

In January 2008, Ann learned that she had a tumour behind her eye. She underwent chemotherapy and radiotherapy and her cancer went into remission, but it returned last February.

In her book Remembering Rachel: The Story of Rachel O'Reilly's Life and Brutal Death, Rose Callaly paid tribute to her daughter Ann's courage in fighting cancer. "I do not know how she has coped so well so far; she is an example to all of us."