[Theresa] and her brother [George] are taking [Theresa]'s son [Nicolas] to the park.
('George', 'Nicolas')
[Theresa] and her brother [George] are taking [Theresa]'s son [Nicolas] to the park.
[{('George', 'nephew', 'Nicolas'): [('George', 'sister', 'Theresa'), ('Theresa', 'son', 'Nicolas')]}]
['sister', 'son']