“Baby Mary”’s mother has been sentenced to just under a year in jail, nearly 40 years after she left her newborn daughter inside a plastic bag in a North Jersey park, prosecutors said Thursday. Mary Crumlich, 57, of South Carolina, was sentenced to 364 days in the Morris County Correctional Facility, followed by two years of probation, the Morris County Prosecutor’s Office said in a statement. The infant, dubbed “Baby Mary,” was found abandoned near a stream along Mount Pleasant Road in Mendham Township on Christmas Eve in 1984. She was wrapped in a towel inside of a plastic bag, her umbilical…