[Theresa] went to the park with her sister [Nancy]. [Nancy] decided not to invite her brother, [Nicholas], though.
('Theresa', 'Nicholas')
[Theresa] went to the park with her sister [Nancy]. [Nancy] decided not to invite her brother, [Nicholas], though.
[{('Theresa', 'brother', 'Nicholas'): [('Theresa', 'sister', 'Nancy'), ('Nancy', 'brother', 'Nicholas')]}]
['sister', 'brother']