She did not return a phone message seeking comment.
“When this relationship took place, school was out, and you had consenting adults,” her attorney Michael DeRiso said. He declined further comment.
Two 18-year-old students told police that Leiseth invited one of them to her home on Shady Glen Drive on May 27 and the other on May 28 and had sex with them, according to a criminal complaint.
The last day of classes was May 27, but the students did not walk at graduation until June 5.
New Brighton police learned of the allegations when someone called Superintendent Joseph Guarino and told him of sexual involvement between two male seniors and a teacher, the complaint said. The district and police investigated and learned from another teacher that Leiseth told her she had slept with two of her senior students.
Moon police interviewed the students and charged Leiseth on Monday.
Eighteen-year-olds can legally consent to sex in Pennsylvania, but police say she committed a crime because the encounters with the male students occurred when Leiseth still had a teacher-student relationship with them.
Guarino said in a statement that Leiseth no longer works for the district. He said officials reported the incidents to law enforcement and state agencies when they learned of the allegations, and cooperated with investigators.
Leiseth began working for the district as a substitute in the middle school in the 2012-13 school year, the complaint said. She worked as a long-term substitute English teacher in the high school in 2013-14.
A preliminary hearing is scheduled for July 22.