By Brad Segall

BRYN MAWR, Pa. (CBS) — A Lower Merion mother is facing homicide charges in connection with a deadly crash in Bryn Mawr earlier this month that killed the driver of a delivery truck.

Prosecutors say Meredith Williams-Earle, 30, who teaches Latin at Interboro High School in Prospect Park, Pa., had her two-year-old son in the back seat of her car while she was driving under the influence and speeding, eventually blowing through a stop sign at the intersection of Morris Avenue and Spring Mill Road.

She struck a delivery van, killing the 72-year-old driver, who was partially ejected and pinned beneath the vehicle.

Montgomery County District Attorney Risa Ferman says Williams-Earle had both prescription drugs and alcohol in her system at the time of the crash.

“What we learned in the investigation is that she had taken Ativan [a sedative] prior to driving. She was feeling some impact from that, and communicated with a friend who suggested that she drink alcohol to reverse the dizzying effect that it was having on her.”

Ferman says the woman’s blood-alcohol level was above the legal limit when the accident occurred.

The charges against her now include homicide-by-vehicle DUI, which carries a mandatory three-year jail sentence.

The child, who was sitting in an improperly installed car seat, was taken to the hospital for non-life-threatening injuries.

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