The Christian Science Monitor, where the 28-year-old worked as a freelancer when she was kidnapped on January 7, said Carroll was warned that she may be killed if she talked with US officials after her release.
After her kidnappers dropped her off at the Iraqi Islamic Party office in Baghdad on Thursday, Carroll was at first reluctant to go with an American military escort to the fortified Green Zone, headquarters of the US military, her newspaper said on Friday.
Her kidnappers said the Green Zone had been infiltrated by militants and Carroll might be killed if she cooperated with the Americans, the Monitor said in a report, quoting the journalist's family.
Scott Peterson, a Baghdad correspondent for the newspaper, convinced Carroll it was safe and persuaded her over the telephone that it was the best course of action, the report said.
Since she was freed, Carroll has met with friends in Baghdad and undergone medical checks, said David Cook, the Monitor's Washington bureau chief.
He said Carroll would return to the United States in the next couple of days to see her family and "decompress" before appearing at the newspaper's Boston headquarters for a celebration and a news conference.
"We'll have a better fix on how she's doing when we [see] her, which we hope will not be too much longer"
Christian Science Monitor newspaper
"We'll have a better fix on how she's doing when we lay eyes on her, which we hope will not be too much longer," Cook told Reuters.
The Monitor, along with Iraqi and US officials, has denied any negotiations took place to secure her release, a week after three Western Christian peace activists were rescued by US-led forces.
Carroll has told Tareq al-Hashemi, the Islamic Party leader whose moderate Sunni group urged her release, that she did not know who kidnapped her. But she said she had been well treated and described her captors as "mujahideen".
According to Carroll, she was kept in a darkened room for most of her captivity. She likened it to living in a "cave" with few sounds and only a trickle of information from the outside world.
Carroll's captors had one final demand the night before her release: In return for her freedom, she had to make a video praising her captors and attacking the United States.
The video, which has sparked criticism against Carroll on conservative internet sites, appeared on a jihadist web site that also shows videos of beheadings and attacks on American forces, the paper said.
Carroll told her father that she felt compelled to make statements strongly critical of George Bush, the US president, and his policy in Iraq to secure her freedom, the newspaper said.