53-year-old Michelle Powell was struck around 8:15 p.m. while trying to cross Cheltenham Avenue near East Mt. Airy Avenue.
The operator of the striking vehicle sped off and remains at large.
On Friday, Powell's sister made an impassioned plea for the driver to surrender to police.
"Look deep down in your heart, in your conscience. This could have been your mother, your sister, your child. I ask you, please, turn yourself in. Don't do this to another family," said Linda McWilliams.
The vehicle that hit Powell is described as a light gray car, possibly an older model Buick LeSabre or Ford Thunderbird with front-end damage.
It had a Pennsylvania tag number J75840J. It's a dealers tag, which makes it tough to trace to a specific car.
"They have restrictions, but they do go from car to car, so they may not be on the same car all the time. That's an issue for us," said Chief John Norris of the Cheltenham Twp. Police.
The driver is described as a black man in his early 20s with "bushy" hair and wearing a tan jacket.
Family members say Powell, a mother of two who lived with her husband in West Oak Lane, worked at the Walmart in the Cedarbrook Plaza where the accident happened.
They say she just left work and think she may have been crossing the street to get something to eat.
Anyone with information is asked to contact the Cheltenham Police at (215) 885-1600.
This is the third fatal hit-and-run incident in Cheltenham Township in less than 18 months. The previous two cases remain unsolved.