The victim - an 18-year-old woman - remains in a serious but stable condition in hospital today, police said.
The teenager was found with gunshot injuries in Hughes Avenue, Bradmore, at around 4.15pm on Saturday and taken to hospital.
A gun was recovered nearby and police enquiries are being carried out to establish whether it is connected to the crime, the force said.
A spokeswoman for West Midlands Police said: "No arrests made as yet and victim remains in a serious but stable condition."
The incident marked the third time a gun has been fired on the region's streets in the past week – after shots were fired in Wolverhampton last Monday and in Bearwood on Wednesday.
The three incidents are not connected, West Midlands Police said.
Two men, aged 19 and 20, remain in hospital today in a stable condition after they were injured in Poplar Road, Bearwood, police confirmed.
Two other men, aged 24 and 22, were both arrested on suspicion of violent disorder and have been bailed pending further enquiries.