Three days after a 12-year-old girl was reported missing, Gwinnett County police have very few clues to her whereabouts.

Pricilla Ristick was last seen around 5:30 p.m. Sunday in a shopping center on Indian Trail Road, near Lilburn. Her uncle told police he left the girl briefly to go into a business, and when he returned, she was gone.

A surveillance camera image released Wednesday show the girl, wearing jeans and holding a jacket, walking alone toward the parking lot. Another picture shows a side view of a white passenger van. Pricilla's family believes she may have gotten into that van.

Gwinnett police said Wednesday there is no indication that Pricilla was taken by force and may have left of her own will.

Pricilla Ristick's uncle, Joey Thompson, told police the girl was selling flowers in the parking lot earlier Sunday. Thompson said other people saw the girl get into a white van, which then drove away, police said.

Thompson told police a woman named Nancy, who Pricilla had befriended a week before, may have been in the white van. But police have little else to go on and no description of Nancy.

The missing girl's mother, Julia Ristick, claimed the girl called a few hours later, Channel 2 Action News is reporting. But police have been unable to confirm the call, Cpl. Edwin Ritter told the AJC Wednesday.

"She told me, ‘Mom, I can't get away,'" Julia Ristick recalled, as her eyes watered.

"I told her, ‘Come home. Try to figure out a way out of there,' and she said, ‘I can't. I don't know where I am,'" the girl's mother told Channel 2.

Julia Ristick said she was telling her daughter to call 911 when the call ended.

Pricilla Ristick is about 4 feet tall and weighs about 95 pounds, police said. She has red hair, police said. She was last seen wearing a gray jacket, blue jeans and black shoes.

Anyone with information is asked to call is 911 or the Gwinnett County Police Department Special Victims Unit at 770-513-5300.

-- Staff writers Kristi E. Swartz and Angel K. Brooks contributed to this report.