A woman confessed to cops that she was the driver involved in a fatal hit-and-run this week in Harlem, and was arrested, police said Friday.

Crystal James told officers Thursday that she believed she might have hit a pedestrian on the FDR Drive near 116th Street with her 2002 Nissan sedan, which had damage to the passenger side, police said.

Earlier that day, Alesha Henderson, 33, was discovered lying on the highway about 5:30 a.m., cops said.

Police found Henderson unresponsive with severe head trauma, and she was pronounced dead at the scene.

James, 27, was arrested and charged with leaving the scene of an accident and failure to exercise due care.