A woman who threatened to cut a 10-year-old girl’s throat with a box cutter will serve 15 days in jail.The woman, Kimberly G. Martin, 35, entered a guilty plea to the reduced charge of simple assault and was directed to serve 15 days of an 11-month, 29-day sentence. She was also ordered to take anger management classes and must stay away from the victim. She was originally charged with aggravated assault, a crime that carries three to six years in prison.Martin was charged after police answered a disturbance call on Yager Road regarding an armed person.