The fatal crash occurred just before 4 p.m. on Aug. 31 at the intersection of Horseblock Road and Montauk Highway in Brookhaven.
Police said Jessica Pistolese, 38, of Mastic, was driving a 2004 Chevrolet Malibu west on Montauk Highway, when she careened into a 2011 Chrysler 300. Her mother, 71-year-old Judith Rivera of East Patchogue, was a front seat passenger and was killed upon impact, police said.
The driver of the Chrysler, Aide Marichal, 51, of Mastic, had been traveling south on Horseblock Road and attempting to make a left turn onto Montauk Highway when she was hit by the Malibu, cops said.
Both Pistolese and Marichal were injured in the smashup. The two women were treated for non-life-threatening injuries at Brookhaven Memorial Hospital in East Patchogue and later released.
Police charged Pistolese with reckless driving. She was released from custody after posting stationhouse bail and will arraigned Nov. 4 at First District Court in Central Islip.
Anyone with information is asked to call Vehicular Crimes detectives at 631-852-6555. The investigation remains ongoing.