A California woman has been charged with allegedly leaving voice-mail messages threatening to bomb, burn and kill people at Georgetown Visitation Preparatory School, after the private, Catholic all-girls high school announced plans to include information about same-sex weddings in its alumnae magazine, according to court filings.

Sonia Tabizada pleaded not guilty Jan. 3 to federal charges of obstructing religious exercise by threat and transmitting bomb threats in interstate commerce, according to court records. She has been jailed since her arrest and faces a Jan. 21 detention review hearing before U.S. District Judge Carl J. Nichols in Washington, records show.

Tabizada’s appointed defense attorney, Carmen D. Hernandez, did not immediately respond to a request for comment.

According to a grand jury indictment returned Dec. 6 and unsealed Jan. 3, Tabizada allegedly left at least two expletive-laden messages around 5:15 a.m. Eastern time on May 15. The messages came two days after Sister Mary Berchmans Hannan, the prestigious Northwest Washington school’s president emerita, announced plans to include news of same-sex unions of alumnae.

The messages included threats to kill students if the magazine didn’t remove “gay motherf-----s.”

The story was first reported by NBC4.

Founded in 1799, Visitation is one of the oldest Catholic girls schools in the United States and teaches about 500 students in four high school grades. Its acknowledgment of same-sex marriage broke with official church teaching on the subject.