[Lillian] played golf with her son [John]. [John]'s sister [Janet] watched with delight.
('Janet', 'Lillian')
[Lillian] played golf with her son [John]. [John]'s sister [Janet] watched with delight.
[{('Janet', 'mother', 'Lillian'): [('Janet', 'brother', 'John'), ('John', 'mother', 'Lillian')]}]
['brother', 'mother']