[Charles] tripped his brother [Theodore] in the living room. [Lena] and her son [Charles] went to the zoo with [Lena]'s brother [Francisco].
('Francisco', 'Theodore')
[Lena] and her son [Charles] went to the zoo with [Lena]'s brother [Francisco]. [Charles] tripped his brother [Theodore] in the living room.
[{('Francisco', 'nephew', 'Theodore'): [('Francisco', 'sister', 'Lena'), ('Lena', 'son', 'Theodore')]}, {('Lena', 'son', 'Theodore'): [('Lena', 'son', 'Charles'), ('Charles', 'brother', 'Theodore')]}]
['sister', 'son', 'brother']