Police say a McKeesport woman was driving more than twice the speed limit when she went through a stop sign and slammed into another vehicle, killing its passenger.

Brittney N. McPherson, 33, had alcohol and marijuana in her system at the time of the Feb. 14 crash that killed Donna DeFrances, 69, of McKeesport, Allegheny County Police said.

McPherson was charged Wednesday with homicide by vehicle while driving under the influence, child endangerment and related offenses.

The two-vehicle crash was reported just before 9 p.m. at the intersection of 24th and Rockwood streets in McKeesport. McPherson was behind the wheel of a Dodge Caravan that collided with a Honda Accord in which DeFrances was riding.

There were four passengers in McPherson’s vehicle, according to court papers. One man and a child were taken to a hospital for treatment. Two other children weren’t hurt, police said. The driver of the Honda was taken to a hospital for treatment of broken bones.

Court papers say McPherson told investigators she had smoked marijuana and drank alcohol before driving and going through a stop sign. Blood tests confirmed that, as did the event data recorder in the minivan, according to the papers. It showed the minivan was traveling 56 mph at the time of the crash, police said. The speed limit is 25 mph.

As of 8 a.m. Thursday, McPherson had not been arraigned. She did not immediately return a message. There was no attorney listed in court records.

DeFrances was a retired certified nursing assistant, according to her obituary. She was survived by three children and three grandchildren.