Just speculating: Could she have left her son in the car and ran into the store ( maybe he was sleeping and thought she wouldn't be long etc) and someone called the police on the child in the car alone and she panicked and ran. Tim Miller also mentioned she didn't look like the pictures they have of her. She probably doesn't have makeup etc with her. <modsnip> All IMO and for the record, I am not saying it is ok to leave a child in the car for any reason.
This is exactly what came to mind for me, but I guess we wait and see. MOO