Police say one of the women actually abducted the girl, signing her out of Bryant Elementary school Monday morning.
They believe the other woman rescued the girl from a home in West Philadelphia and dropped her off a playground in Upper Darby where she was eventually found.
Police have not identified any of the suspects by name.
WATCH the news conference LIVE on 6abc.com beginning at 1:00 p.m.
WATCH: Surveillance video from the school
The girl went missing Monday morning after her mother dropped her off at Bryant Elementary School in West Philadelphia. That was at 8:45 a.m.
Police say minutes later, a woman dressed in Muslim garb which only showed her eyes, signed in with the name "Tiffany."
The woman was told to go to the school's office. But police say she went to the girl's classroom instead, telling the substitute teacher on duty she was the girl's mother and was taking her to breakfast.
When the substitute teacher challenged her, police say the woman got indignant, saying, "I signed what I was supposed to sign, I've got other appointments and I do not need to put up with your nonsense."
That woman, who is now the subject of an intense search, is described as a black female in her 20s, standing about 5'5" to 5'6" tall. Police say she may have been pregnant. She is seen on surveillance video walking with the girl from her classroom at about 8:50 a.m.
The Fraternal Order of Police is offering a $5,000 reward for tips leading to the woman's arrest.
Sources say the girl was then taken from her school to a home at an unknown location where she was blindfolded. Investigators said that this did not appear to be a random act, but rather the girl was targeted, noting that the woman knew where to go and asked for the girl by name.
Authorities say when someone from the girl's daycare arrived to pick her up at 3:00 p.m., they finally realized something was wrong. An Amber Alert was then issued for the girl on Monday evening.
She was found by a passerby named Nelson Mandela Myers at 4:40 a.m. Tuesday at a playground in Upper Darby, Delaware County, 1.5 miles away from Bryant Elementary School.
She was crying, wet, and wearing only a t-shirt.
Upper Darby police say Myers was on his way to work when he heard the girl's cries Tuesday morning and found her under a playground sliding board near 69th Street and Marshall Road, cold and upset.
On Tuesday night, Mayor Michael Nutter announced Myers would receive the $10,000 reward that was being offered for information leading to the girl's return.
Once found, the girl was taken to Children's Hospital of Philadelphia where she was evaluated, reunited with her mother, and released.
The child has had some preliminary interviews after being released from the hospital.
Police, covering all bases in this investigation, conducted a lie detector test on the girl's father. He passed. After being released from the hospital, the girl was carried home in her mother's arms and surrounded by detectives.
"[I'm] very relieved," the mother said as she walked inside the home with her daughter.
Meantime, a spokesperson for the Philadelphia School District admitted that Bryant Elementary did not follow proper protocol for school visitors. The substitute teacher involved has been suspended and the school district said an investigation has begun into exactly how this happened.
The girl's family is searching for answers from the school.
"There's no excuse. 8:00 a.m., crowded, no excuse that a child disappeared five minutes after she got there," the girl's uncle said.
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VIDEO: Police press conference on the girl's abduction
