The shooting took place at about 9:56 p.m. in the 800-block of West 59th Street.
Police said two dark-colored vehicles drove past, and suspects inside fired shots at each other.
The woman, who was sitting on a bench, was caught in the crossfire and shot in the chest, police said. She was taken to the University of Chicago, where she was listed in critical condition.
She remained hospitalized later Tuesday.
Surveillance video captured the moments before the shooting. Police said people inside two vehicles were exchanging gunfire as they turned onto 59th Street when the woman was struck. Authorities said the intended targets were in the vehicles, but the gunfire hit the woman instead.
Anthony Allen, a security guard at a nearby gas station, said he heard the gunshots and ran across the street to assist the victim.
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"She hollered for help, and she's not on the ground. She's leaning over, and I seen her. I open up her coat to see she's bleeding," Allen said.
Allen said the woman told him it was her birthday.
"She was corroborating with me and talking to me and she said it was her birthday. She was telling me it's not supposed to happen, and I told her only God knows that," Allen said.
In the aftermath of the shooting, the anti-violence organization A Knock at Midnight spent the day canvassing the Englewood neighborhood and sharing resources aimed at preventing future violence.
"We try to engage the community, offer resources and mental health assistance, even education or employment. Something to change the narrative because a lot of our homes are broken, so we try to show them it's not the end, and there's hope out there," said Breyonna Roberts, a victim service advocate.
Area One detectives are investigating.
No arrested have been made.
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