Officers say it happened around 8 p.m. on the 100 block of East Albanus Street in the city's Olney neighborhood.
According to police, a 2-year-old girl was shot twice, once in each leg.
She was transported by private vehicle to Einstein Medical Center, where she was placed in stable condition.
The 30-year-old mother was shot multiple times, including once in the head, police say.
Police transported her to Einstein Medical Center, where she was placed in extremely critical condition.
Officers believe the victims were caught in the crossfire of a shootout between two groups.
"She was sitting on her porch with her 2-year-old," noted Deputy Commissioner James Kelley. "We believe they were both innocent victims, as sad as that is."
Sources tell Action News that a neighbor with a gun permit fired back at the suspect in defense of the victims. That person was brought in to talk with police as part of the investigation.
A suspect has not yet been taken into custody.