[Nancy] could n't wait to get off the plane to see her mother, [Louise]. [Louise] took her younger sister [Heidi] to the carnival last weekend.
('Heidi', 'Nancy')
[Louise] took her younger sister [Heidi] to the carnival last weekend. [Nancy] could n't wait to get off the plane to see her mother, [Louise].
[{('Heidi', 'mother', 'Nancy'): [('Heidi', 'sister', 'Louise'), ('Louise', 'mother', 'Nancy')]}]
['sister', 'mother']