The shooting took place at about 10:32 p.m. in the 1200-block of South Wabash Avenue.
A witness told police there was an altercation between the girl and a suspect which became physical and a gun went off.
The victim was wounded in the thigh and transported to Northwestern Memorial Hospital, where she was in good condition, police said.
Jeff Clevinger was on a nearby CTA platform at the time of the shooting.
"I heard a lot of noise going on and an argument so I was concerned someone was getting into a fight or something like that," Clevinger said. "I was getting ready to call the police and by the time I called police, there were two gunshots. I was looking down and there was a lady laying on the ground and there was like ten people around her trying help her out and stop the bleeding."
A neighbor said he's now left with his own questions about what happened.
"I think it's unfortunate, but then it goes down a who, what, when, where and why?" the neighbor said.
Police said they were speaking with a person of interest on Wednesday.
Area Three detectives are investigating.
In a statement, Jewel said, "We are working with the Chicago Police Department and cannot comment on the investigation."
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