The 33-year-old died in a Tupelo hospice house.
Her death came from injuries sustained in the April 22 accident that killed 17-year-old April Stamper, who had just attended her prom, according to Lee County Coroner Carolyn Gillentine-Green.
Arnold reportedly was driving down the wrong side of Highway 78 when her vehicle collided head-on with the truck driven by another Mantachie student. In all, three vehicles were involved in the accident and three others also were injured.
According to Mississippi Highway Patrolmen, they suspected Arnold of drinking before the accident, saying that could have been the main factor that caused the wreck.
Results from a toxicology report done on Arnold were released, according to Trooper Ray Hall.
Stamper and the other teens were driving back to Mantachie after going to Fulton to get ice cream when the accident occurred.