She said it was a "lovely service" which had given her and her father a "bit of peace" and some closure.
"On Friday we were also taken up to the tribe's village about an hour's drive away. They told us they had adopted us into their family and reassured us they would take care of Cindy's spirit.
"They also told us they had given Cindy an Aboriginal name 'Yimara' which means flower, a beautiful red flower, which is really fitting.
"Aboriginal people are very spiritual, and it's really reassuring to know that Cindy's spirit is in really good hands."
Mrs Annett said her sister's tragic death had traumatised the family.
"It's the stuff of nightmares, it's really difficult talking about what happened ... and picturing what happened to Cindy is like reliving a re-occurring nightmare."
The attack sparked calls from some quarters for croc-shooting safaris to cull numbers.
However, Cindy's parents said they did they want to see any crocodiles harmed.
The 4.3m crocodile suspected of being responsible for the attack has since been caught and killed, and found to contain human remains which police believed were that of a woman.
"People might say Cindy made a stupid mistake," said Mrs Annett. "But we were told that the beach area where she was wading was a popular swimming spot used by many locals including the indigenous community."
Mr and Mr Waldron said the family were still coming to terms with what happened to their "darling daughter" who was "loved by everyone".
Mrs Annett said her sister never had a bad word to say about anyone. "She only ever saw the good in everybody.
"People tend to say nice things when someone has passed away, but Cindy was truly one of life's wonderful people. I was really close to my little, big sister.
"We will miss her deeply."
Kiwi-born Ms Waldron had lived in Australia for 26 years but phoned her parents and sister every week without fail, her father said. The family last heard from her a week before she was taken from them.
"Cindy was the happiest she had ever been," her sister said.
Ms Waldron's mother, Heather, said the family were still discussing arrangements and a funeral would be held "very soon". Cindy's Australian friends also planned to hold a farewell for her on June 19 - it would have been her daughter's 47th birthday.
Mrs Waldron said: "We want to say a big thank you to all the people who have supported us here at home and in Australia and our family now asks to be left alone to grieve in private."
In a year's time the family planned to go back to Thornton Beach to erect a seat at the spot where Cindy was taken and hold a service to celebrate her life.