[Marie] and her sister [Tracy] tried to get their sister [Beverly] to go to the movies with them. [Beverly] already had plans to see the movie with her brother [Robert]. [Pedro] took his brother [Robert] out to get drinks after a long work week.
('Pedro', 'Marie')
[Pedro] took his brother [Robert] out to get drinks after a long work week. [Marie] and her sister [Tracy] tried to get their sister [Beverly] to go to the movies with them. [Beverly] already had plans to see the movie with her brother [Robert].
[{('Pedro', 'sister', 'Marie'): [('Pedro', 'sister', 'Tracy'), ('Tracy', 'sister', 'Marie')]}, {('Tracy', 'sister', 'Marie'): [('Tracy', 'sister', 'Beverly'), ('Beverly', 'sister', 'Marie')]}, {('Pedro', 'sister', 'Tracy'): [('Pedro', 'brother', 'Robert'), ('Robert', 'sister', 'Tracy')]}]
['brother', 'sister', 'sister', 'sister']