NEW CITY - A grand jury indicted a former teacher's aide from Warwick on Monday on charges she brought a loaded handgun into a school in March, Rockland County District Attorney Thomas P. Zugibe said.Gillian Jeffords, 24, faces a felony charge of criminal possession of a weapon on school grounds and three misdemeanor counts of endangering the welfare of a child, according to a news release from Zugibe.Jeffords worked as a teacher’s aide at the Jesse J.