PHILADELPHIA -- A woman accused of dumping her quadriplegic son in the woods so she could spend the week with her out-of-state boyfriend was hospitalized Monday for a third day in Maryland while Philadelphia police awaited her release to arrest her.

Nyia Parler has been hospitalized for undisclosed reasons since late Friday, just hours after her 21-year-old son was found in a pile of wet leaves, next to his wheelchair and a Bible, authorities said.

Police believe he had been there all week - exposed to the cold, rainy weather and to wild animals. He was found around the corner from his home by a person who saw the wheelchair and went to investigate. If the person hadn't done that, Philadelphia police Lt. John Walker said, "this kid would have died a miserable death."

The son remained in stable condition Monday at Children's Hospital of Philadelphia after being treated for dehydration, malnutrition and abrasions, Walker said. The son has cerebral palsy.

Parler, 41, told concerned relatives last week that she had taken her son with her when she went to visit her boyfriend, police said. The son attends a public high school that had inquired about his absences, they said.

An arrest warrant issued Saturday charges Parler with aggravated assault, kidnapping, neglect of a care-dependent person and other counts. Philadelphia police did not expect to arrest Parler until she was cleared for release from the hospital and charged in Maryland as a fugitive. They would then seek to have her extradited.

Police in Maryland would not discuss details of how the mother came to be hospitalized.

Captain Paul Starks of the Montgomery County Sheriff's Department said Monday that security reasons prevented him from disclosing the name of the facility where Parler is being held and medical privacy laws prevented him from discussing Parler's health condition.

Police contend that Parler boarded a bus to visit her boyfriend after leaving her son in the woods near their west Philadelphia home. The boyfriend thought that family members were watching the son, police said.

"She pushes him about 150 yards from the highway into the wooded area, takes him out of wheelchair, lays him on the ground, puts a blanket over him and leaves a Bible with him, and then just walks away," Walker said Saturday. "It's only by the grace of God that he survived this."

Parler also has a 16-year-old son who is now in the care of relatives, police said. It isn't clear if she has a lawyer who could comment on the charges.

Neighbor Oscar Robinson told reporters that Parler seemed like a good mother. He said she was never late to pick him up at the bus stop.

"He seemed content," Robinson said, "and he responded to her."