[April] asked her sister [Ann] to play with her. [Ann] did n't want to, she wanted to play with her sister [Andrea] instead.
('April', 'Andrea')
[April] asked her sister [Ann] to play with her. [Ann] did n't want to, she wanted to play with her sister [Andrea] instead.
[{('April', 'sister', 'Andrea'): [('April', 'sister', 'Ann'), ('Ann', 'sister', 'Andrea')]}]
['sister', 'sister']