The 46-year-old New Zealander has not been seen since she was dragged under the water at Thornton Beach in Daintree National Park, north of Cairns, after venturing into the water with friend Leeann Mitchell late on Sunday night.
Both women now live in Australia.
As authorities continue what has now become a recovery operation, Ms Waldron's father and sister had arrived in Cairns to be closer to where she spent her final days and say goodbye.
"They were best friends and they hadn't seen each other for a while," Ms Waldron's sister Anna-Lee Annett said yesterday.
"They did something silly."
Ms Mitchell, who made frantic attempts to rescue Ms Waldron and received minor injuries, had spoken to Ms Annett.
"(It was the) most difficult conversation of my entire life, but I needed to have that conversation," Ms Annett said.
The women had reportedly travelled to the tropics to celebrate Ms Mitchell's cancer treatment coming to an end.
Family members, including Ms Waldron's father Pat, have visited Thornton Beach.
But Ms Annett said the crocodile should not be hunted down after authorities set three traps.
The incident has prompted the state government to allocate an extra $A5.8 million ($NZ6.1 million) over three years in next week's budget for crocodile management - including comprehensive population surveys - after Environment Minister Steven Miles admitted his department did not know whether numbers were rising or falling in parts of the state.
