The Trio and a small, few including Blaise Zabini, Theodore Nott and Pansy Parkinson, were the only ones to heavily defend the mother and son. Hermione spent many late nights researching and devising statements to free them. She was relieved when Narcissa was cleared. Harry’s record of her defiance with Voldemort and what that meant for him and the war seemed to sway the jury into freeing her. It helped that Narcissa hadn’t done anything untoward while under Voldemort’s reign.