[Pedro] took his daughter [Rebecca] to the zoo on Saturday. [Pedro]'s wife [Dorothy] could n't come as she had to work that day. [Robert] and her brother [Antonio] were playing in the park. [Antonio] saw his sister [Dorothy] getting ice cream and wanted some too.
('Robert', 'Rebecca')
[Robert] and her brother [Antonio] were playing in the park. [Antonio] saw his sister [Dorothy] getting ice cream and wanted some too. [Pedro] took his daughter [Rebecca] to the zoo on Saturday. [Pedro]'s wife [Dorothy] could n't come as she had to work that day.
[{('Robert', 'niece', 'Rebecca'): [('Robert', 'sister', 'Dorothy'), ('Dorothy', 'daughter', 'Rebecca')]}, {('Robert', 'sister', 'Dorothy'): [('Robert', 'brother', 'Antonio'), ('Antonio', 'sister', 'Dorothy')]}, {('Dorothy', 'daughter', 'Rebecca'): [('Dorothy', 'husband', 'Pedro'), ('Pedro', 'daughter', 'Rebecca')]}]
['brother', 'sister', 'husband', 'daughter']