She was shot in the back but managed to run about a block before she collapsed. She died at a hospital.
A 16-year-old boy was wounded in the attack.
Pendleton, who did not have a criminal record, was probably not the intended target.
"Never in a million years did I think I would get a call that my own baby had been gunned down," Pendleton's mother, Cleo Cowley, was quoted as saying.