[Janet] is a sister of [John]. [George] took his son [John] for boxing lessons. He felt the boy needed to toughen up.
('George', 'Janet')
[George] took his son [John] for boxing lessons. He felt the boy needed to toughen up. [Janet] is a sister of [John].
[{('George', 'daughter', 'Janet'): [('George', 'son', 'John'), ('John', 'sister', 'Janet')]}]
['son', 'sister']