Elisa Baker, the stepmother of Zahra Clare Baker, has been talking with investigators after her lawyer approached police offering her help, said Maj. Clyde Deal, deputy police chief in Hickory where the child was reported missing Oct. 9.
Police believe the girl is dead. She uses hearing aids and has a prosthetic leg because of bone cancer. Authorities in recent weeks have combed wooded areas and a landfill for evidence or her body.
Deal said Tuesday that Elisa Baker, 42, was taken earlier this week to a home where she once lived. But he declined to elaborate.
"We're working with her attorney to see what information she has and what she is willing to share. We're treating her like every other source of information," he said.
A telephone message left for Elisa Baker's attorney, Scott Reilly, was not immediately returned.
The stepmother has been charged with obstruction of justice. Police said she acknowledged to writing a bogus ransom note found at the scene of a fire in the family's back yard on the day Zahra Clare Baker was reported missing.
The girl's father, Adam Baker, was arrested Monday on unrelated charges. He and his daughter are from Australia. He and his daughter moved to North Carolina in 2008 after he married Elisa Baker, whom he had met on the Internet.
Adam Baker, 33, is facing one count each of assault with a deadly weapon and failure to return rental property, two counts of communicating threats and five counts of writing worthless checks, authorities said.
The timing of his arrest raises questions because the charges against him were filed over the past few months. Hickory Police Chief Tom Adkins had said authorities delayed taking action because he was cooperating with police.
Deal said investigators haven't talked to Adam Baker since his arrest. He also said Adam Baker did not have an attorney.
Adam Baker was being held in a western North Carolina jail on $7,000 bond. Elisa Baker is at the same jail.
Police have not found the girl's body and haven't charged anyone with killing her. A three-day search of a landfill last week failed to turn up any evidence.