"Obviously how she came to be at the showgrounds will be part of the investigation.
"It's one of those dreams that came true ... the greatest possible outcome for everyone.''
Chloe's mother Tammy O'Donnell rushed to her daughter at the Bundaberg Base Hospital where she was checked over.
''(I'm) over the world; there is no other word to really describe how I'm feeling, just overjoyed,'' Ms O'Donnell told reporters.
She said she cuddled her daughter, who came through her ordeal physically fine but "really tired''.
"I was just in tears. I didn't care if she woke up or not and then I just laid on the bed with her and gave her cuddles for a while and then we just came home to let everyone know,'' said the mother of four.
"She opened her eyes a little bit and (said) 'Mummy want to go home now' and passed out.''
Investigations are continuing.
Police State Crime Command officers hope to interview Chloe on Saturday.
"The last couple of days our focus has been locating her and locating her safe and well,'' Insp Gutridge said.
"Now we will transition to the investigation phase and focus more on that, as to the circumstance of her disappearance.
"We're sincerely hoping to speak to Chloe and anyone that might have any information that can help us.''
Earlier, police briefing the media gathered in the tiny Queensland town described Chloe's safe return as a "an absolute miracle".
Chloe was found at Childers showgrounds at around 1:00am Saturday local time - about 42 hours after going missing.
The toddler was reportedly uninjured, but was transported to Bundaberg Hospital as a precaution where she has already been reunited with her elated parents, mother Tammy and father Garth.
"It's one of those dreams that came true ... the greatest possible outcome for everyone," said Inspector Kevin Guthridge.
"We have no idea as to how she came to be here. We are looking at every aspect of that and maintaining a very open mind.
"It is an absolute miracle she has returned to us."
Meanwhile, police have been given security footage from a residential CCTV camera which is understood to show two men and a young child walking about 200 yards from where Chloe disappeared.
Local resident Les Fennell, who passed the CCTV data to police, said the video showed the men and a young child - who could not be identified as being a boy or a girl - walking south by the railway line.
He told the Courier Mail newspaper that the child was walking about 15 yards ahead of the men as they passed behind a toilet block as dawn approached.
Some 20 minutes later the men returned north in the direction they had come but this time without the child.
"The sun had just started coming up...and it was about the same time the child was missing.'
Mr Fennell said the child seemed to know the men as he or she appeared to be leading the way.
"She or he was very small. The child looked like it knew where it was going and the two men followed."
Chloe's disappearance had sparked a huge search effort, with her distraught parents fearing she'd been snatched from the house. Police had issued a child abduction alert, and notified ports and airport to be on the lookout for the little girl.
In the end, Chloe was found close to the house, which backs onto the showgrounds in the small town of Childers, at about 1am (4pm London time).
She had been taken to Bundaberg Hospital, north of Childers, for a medical examination.
Police have yet to comment on the circumstances surrounding the child's disappearance.
"She wandered back to where the crime scene had been set up," Inspector Gutteridge said.
Police are expected to learn from Chloe's mother - who will 'interview' her daughter - just where she has been and who took her away.
The disappearance had rocked the community, with the 1,500 residents who call Childers home devastated by the news.
Chloe's father Garth had told reporters there was a footprint on his vehicle's roof, which was parked in the driveway of their Ridgeway St home underneath the ajar window.
Detectives had always believed Chloe, whether alone or in the keep of an abductor, hasn't ventured far from the home.
They continued to focus their search efforts on Childers and its immediate surrounds, but had turned up nothing in the 42 hours since the child went missing.
Police had searched throughout the night using an infra-red camera without success - and today scores of volunteers and police on foot, motor bikes and horses had continued the hunt around the town and in nearby bushland.
"I don't think there's any possible way she's wandered off," Mr Campbell had told the media. "She wouldn't leave the yard by herself."
He said the family usually closed the windows of their Childers home at dusk each night to keep out mosquitoes, but he believes that one of the latches had not caught.
"That's why we are blaming ourselves," he'd said, fighting back tears.
Police issued a "child abduction alert" shortly after 9am on Thursday and requested the message be broadcast on local radios every 15 minutes.
The disappearance sparked comparisons with that of British toddler Madeleine McCann who went missing from her parents' apartment in Praia da Luz, Portugal in May 2007. She was also three-years-old at the time.
In Childers - roughly 50km south of Bundaberg - a desperate search had been launched as State Emergency Services volunteers joined police in scouring the locale. A major alert for Chloe was also put out at all airports and sea ports.
Mr Campbell said that while Chloe and her two older sisters, Janae, eight, and Britney, five, have their own room in the house, on Wednesday all three girls slept in the lounge.
"When Janae woke to go to the toilet in the morning, Chloe wasn't in the lounge room," he said. Janae, he said, had then thought that her younger sister had sneaked into her parents' room because she had not been well lately.
Melissa Small, a "close family friend" of the Campbells, told News Corp the toddler's window was left open and that alarm bells were raised when her parents discovered she wasn't there this morning.
"The parents put the kids to bed last night. They went to sleep about one o'clock in the morning after watching TV. They have woken up at seven o'clock and (Chloe) was not in bed," she told reporters.
"There's a footprint on the roof of the car to get through to the window.
"The window was open and her blanket and teddy bear, a grey blanket and a blue teddy bear, has been taken with her."
Ms Small referred to a car parked underneath Chloe's window which could have been used to access it. She described Chloe's mother Tammy as "an absolute mess".
Local butcher Ken Gooden said helicopters had been assisting with the mission since roughly 8am.
He described the Campbells as "a young family of three or four" who shop regularly in town.
"It's just like anything, you just serve them and don't think about it until something like this happens," he said.
The toddler's mysterious disappearance had brought Childers to a halt.
The case has also reminded locals of the tragic disappearance of four-year-old Eeva Dorendahl and her father Greg Hutchings. The duo went missing from Pottsville - on the Queensland/New South Wales border - in early January, with police discovering their bodies 17 days later.
Their disappearance made international headlines as details of a dispute surrounding young Eeva came to light.
Childers, where today's search for missing Chloe has intensified, was also in headlines around the world 14 years ago after the Childers Palace Backpackers Hostel went up in flames on June 23, 2000, killing 15 backpackers.
Later Robert Long was arrested for starting the fire and charged with murder. He was sentenced to life in prison.
- The Daily Mail with additional reporting from AAP
