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