A 39-year-old teacher has been charged with having a sexual relationship with one of her underage students during a two-year period, the Los Angeles County District Attorney’s Office has announced.

The teacher, Elizabeth Ann Brewer, 40, of Culver City, faces three counts of sexual penetration by foreign object, two counts of oral copulation and one count of forcible oral copulation. Brewer pleaded not guilty on Dec. 29 and is due to return to court on Jan. 20.

The defendant allegedly sustained a sexual relationship with a 16-year-old student at Notre Dame Academy, a West Los Angeles all-girl private school, between January 2004 and December 2006, prosecutors said.

If convicted as charged, the defendant faces a possible maximum sentence of 21 years in state prison.

The case remains under investigation by the Culver City Police Department.