[George] is in the sixth grade. He looks up to his sister [Nancy], who is in the seventh. [Dale] went to the baseball game with his brother [George].
('Dale', 'Nancy')
[Dale] went to the baseball game with his brother [George]. [George] is in the sixth grade. He looks up to his sister [Nancy], who is in the seventh.
[{('Dale', 'sister', 'Nancy'): [('Dale', 'brother', 'George'), ('George', 'sister', 'Nancy')]}]
['brother', 'sister']