Kate Lohan pleaded guilty to one count of committing assault while on board an aircraft, according to United States Attorney Kenneth Polite.
According to court documents, the 33-year-old stepmother of actress Lindsay Lohan threatened to slit a woman's throat on a JetBlue flight from Fort Lauderdale to Los Angeles Nov. 25.
Court documents say she became disruptive before the flight took off when a flight attendant asked her to put her seat in the upright position.
Witnesses say she later threw a cell phone at one of the flight attendants during the flight. The crew diverted the flight to New Orleans as a result.
U.S. Magistrate Judge Joseph C. Wilkinson, Jr. sentenced Lohan to one year of probation with continued substance abuse treatment. He also ordered her to pay $7,212 restitution for costs associated with diverting the flight.