Police say the triple shooting occurred around 9:40 p.m. along the 1600 block of South 18th Street.
Authorities say the 6-year-old girl was shot twice in the legs. She is in stable condition at Children's Hospital of Philadelphia.
A 17-year-old male and a 23-year-old female were taken to Methodist Hospital by private vehicle; they are also in stable condition.
Police are investigating.