[Wesley] and her sister [Cindy] decided to take a trip to Mexico together. [Wesley] and his sister [Lynn] went to the park. [David] is looking for a good gift for her sister [Cindy].
('David', 'Lynn')
[David] is looking for a good gift for her sister [Cindy]. [Wesley] and her sister [Cindy] decided to take a trip to Mexico together. [Wesley] and his sister [Lynn] went to the park.
[{('David', 'sister', 'Lynn'): [('David', 'brother', 'Wesley'), ('Wesley', 'sister', 'Lynn')]}, {('David', 'brother', 'Wesley'): [('David', 'sister', 'Cindy'), ('Cindy', 'brother', 'Wesley')]}]
['sister', 'brother', 'sister']