Maryanne

Mary Ann was the careless driver of the boat and was the girl that accidentally killed John Baker and injured his children Angela and Peter.

Background
Maryanne may have been a camper or counselor at Camp Arawak. She seemed at least flirtatious with Craig.

Sleepaway Camp (1983)
While enjoying a summer day on the lake in 1975, Maryanne begged Craig to let her drive while Dolores water skiied behind. Craig let her drive and they soon came upon the Baker family in the water. Maryanne was too inexperienced to avoid them and was responsible for killing John Baker and injuring his daughter Angela and his son Peter.

Character
Maryanne may represent teenage carelessness.

Behind the Scenes

 * The script refers to her as "Maryanne," while the end credits list her as "Mary Ann."
 * Alyson Mord, who played Maryanne, was Felissa Rose's closest friend on set.