story: [Nancy] and her daughter [Maria] are entering the competition together. [Preston] is in the sixth grade. He looks up to his sister [Nancy], who is in the seventh. [Nancy] loves cooking for her son. His name is [Robert].
query: ('Preston', 'Maria')
clean_story: [Preston] is in the sixth grade. He looks up to his sister [Nancy], who is in the seventh. [Nancy] and her daughter [Maria] are entering the competition together.
proof_state: [{('Preston', 'niece', 'Maria'): [('Preston', 'sister', 'Nancy'), ('Nancy', 'daughter', 'Maria')]}]