[David] needed to go to the store. [David] asked her sister [Cindy] for a ride. [Richard] and his sister [Natasha] went to the movies to watch the newest superhero flick. [Cindy] took her daughter [Natasha] to see her very first ballet performance.
('Richard', 'David')
[Richard] and his sister [Natasha] went to the movies to watch the newest superhero flick. [Cindy] took her daughter [Natasha] to see her very first ballet performance. [David] needed to go to the store. [David] asked her sister [Cindy] for a ride.
[{('Richard', 'aunt', 'David'): [('Richard', 'mother', 'Cindy'), ('Cindy', 'sister', 'David')]}, {('Richard', 'mother', 'Cindy'): [('Richard', 'sister', 'Natasha'), ('Natasha', 'mother', 'Cindy')]}]
['sister', 'mother', 'sister']