[Amy] asked her sister [Lillian] if she could come over for dinner. [Lillian] told her she could n't, because she had to care for her sick son, [John].
('Amy', 'John')
[Amy] asked her sister [Lillian] if she could come over for dinner. [Lillian] told her she could n't, because she had to care for her sick son, [John].
[{('Amy', 'nephew', 'John'): [('Amy', 'sister', 'Lillian'), ('Lillian', 'son', 'John')]}]
['sister', 'son']