Elizabeth Brewer, 39, faces three counts of sexual penetration by a foreign object, two counts of oral copulation and one count of forcible oral copulation.
Brewer pleaded not guilty Monday. She is due back in court on Jan. 20.
Notre Dame Academy is a Catholic college preparatory school for girls in West Los Angeles.
The case remains under investigation by the Culver City Police Department. If convicted, Brewer faces a maximum sentence of 21 years in state prison.