According to the article:
The teen was shot in the left leg and sustained a through-and-through injury. She was taken to Northwestern University Medical Center in fair condition, police said.
She appears to have been an unintended target.
From a related article:
At 4:05 p.m. police were called to the 4800 block of South Drexel Boulevard because a 16-year-old girl had been shot in the left thigh, according to a Prairie District police lieutenant..
Investigators determined that someone inside a black SUV fired the shots that hit the teen, who was standing with other people in front of a building at the Drexel address.