Question: who is gamora's sister in guardians of the galaxy
[{'answer': 'Karen Gillan portrays Nebula', 'provenance': [{'wikipedia_id': '6377657', 'title': 'Nebula (comics)', 'start_paragraph_id': 31, 'start_character': 0, 'end_paragraph_id': 31, 'end_character': 28, 'bleu_score': 1.0, 'section': 'Section::::In other media.:Film.\n'}]}, {'provenance': [{'wikipedia_id': '6377657', 'title': 'Nebula (comics)', 'start_paragraph_id': 31, 'start_character': 0, 'end_paragraph_id': 31, 'end_character': 431, 'bleu_score': 0.9328730072843131, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12817426411909689926}, 'section': 'Section::::In other media.:Film.\n'}]}]