A 49-year-old Dracut woman will serve three years of probation after pleading guilty to assaulting and threatening a disabled nun. Joanne Miele was hired by Sister Robin McCarthy last year as a temporary home health aide, but was fired when McCarthy, who has cerebral palsy, said she arrived at work under the influence of drugs. Following her termination, Miele assaulted the nun in January 2012. That March, McCarthy took out a harassment prevention order against Miele, but was later approached and threatened by Miele during a prayer meeting. Miele pleaded guilty in Lowell District Court to assault and battery on a disabled person, aggravated assault and battery, violation of a harassment prevention order, and witness intimidation.