[Lillian] asked her two sisters [Theresa] and [Nancy] if they were free for coffee this coming weekend.
('Nancy', 'Theresa')
[Lillian] asked her two sisters [Theresa] and [Nancy] if they were free for coffee this coming weekend.
[{('Nancy', 'sister', 'Theresa'): [('Nancy', 'sister', 'Lillian'), ('Lillian', 'sister', 'Theresa')]}]
['sister', 'sister']