A Burlington woman accused of killing her neighbor’s 6-month-old baby girl a year ago at an unlicensed day care program she was running out of her apartment was ordered held without bail yesterday, officials said.Pallavi Macharla, 40, was arrested at her home yesterday afternoon and arraigned on charges of murder and operating an unlicensed child care program in Middlesex Superior Court, according to Middlesex District Attorney Marian Ryan.