The Australian further reports Bev McNally, another former babysitter for the Dawson's, has also given a statement to police, along with a third woman who recently met with detectives for the first time.
"They corroborate Joanne's evidence," a senior police source said.
Lynette Dawson's body has never been found.
Police now believe she was buried in bushland in Sydney's north, despite a recent excavation of her former Bayview home as police searched for evidence.
McNally, who frequently looked after the couple's two young daughters Shanelle and Sherryn, told the Manly Daily: "It feels surreal...His daughters have had their world re-shattered. We have to feel for them too."
Ms McNally said she was only speaking to the older Dawson girl, Shanelle, last night and had texted her this morning following news of her father’s arrest.
“She’s coping. She was trying to prepare herself but nothing prepares you for this,” Ms McNally told the Telegraph.
Detectives from the NSW homicide squad began reinvestigating her suspected murder in 2015, calling on the Office of the Director of Public Prosecutions to review their brief of evidence in April this year.
Police spent in excess of $500,000 on digging in the grounds of the couple’s former Bayview home in the hope of finding her body or any new evidence, but nothing was found.