The girls admitted a charge of kidnap after they walked off with the child and were only found an hour and a half later, three miles away, after their descriptions were circulated in a major police operation.
It emerged their victim was the second child they intended to grab from the Primark in Newcastle, having tried unsuccessfully to trick another little girl’s mother.
At a previous court hearing, details emerged of alarming internet searches about “rape” that police found on a tablet computer.
A charge of kidnap with intent to commit a relevant sexual offence was discontinued by the Crown Prosecution Service, as the teenagers’ pleas to the alternative kidnap charge were accepted.
The kidnapped child was reunited with her mother unharmed after the abductors were traced by CCTV camera operators.
They had also stolen dummies, baby milk and a bottle to use as part of their plan on April 13.
After the girls admitted the charges at a youth court at North Tyneside, the little girl’s father said her mother will “never forget the guilt” of losing her.
He said: “Her mother was on the phone and our daughter was in her pram. They offered her sweets, she was hysterical and they got her out and started playing with her around the shop.”
He said his daughter was unharmed and unlikely to remember anything of the abduction.
The kidnappers’ guilty pleas still did not explain their motive, he said.
He also praised the operation to find his daughter, saying: “Thankfully, the police did an amazing job.”
The girls have no criminal record and have never been arrested or cautioned.
District Judge Roger Elsey adjourned the case for reports to be made.
Referring to the searches on the computer, he said: “There is some very concerning material on the tablet that was recovered.”
The girls were remanded into the care of the local authority.