UPDATE: The Allegheny County Sheriff's Office says McPherson turned herself in Thursday morning.
Police say a McKeesport woman who speeded through a stop sign and hit another vehicle, killing the driver, had alcohol and marijuana in her system.
33-year-old Brittney McPherson was charged Wednesday with homicide by vehicle while driving under the influence and other offenses.
She was driving a Dodge Caravan with another adult and three children in the vehicle when it crashed.
The other vehicle, a Honda Accord had two adults in the vehicle, including 69-year-old Donna DeFrances who was killed at the intersection of 24th and Rockwood streets in McKeesport.
An adult and one child in the Caravan were taken to the hospital in stable condition.
Investigators say McPherson was going 56 miles per hour in a 25 MPH zone at the time of the crash.