[Beverly] and her sister [Dorothy] braided each other's hair before school. [Samuel] was so excited to introduce his new girlfriend to his mother, [Beverly]. [Robert]'s sister, [Dorothy], participated in the dance contest. [Samuel] and his brother [Michael] were playing tag in the park.
('Robert', 'Michael')
[Robert]'s sister, [Dorothy], participated in the dance contest. [Beverly] and her sister [Dorothy] braided each other's hair before school. [Samuel] was so excited to introduce his new girlfriend to his mother, [Beverly]. [Samuel] and his brother [Michael] were playing tag in the park.
[{('Robert', 'nephew', 'Michael'): [('Robert', 'sister', 'Beverly'), ('Beverly', 'son', 'Michael')]}, {('Beverly', 'son', 'Michael'): [('Beverly', 'son', 'Samuel'), ('Samuel', 'brother', 'Michael')]}, {('Robert', 'sister', 'Beverly'): [('Robert', 'sister', 'Dorothy'), ('Dorothy', 'sister', 'Beverly')]}]
['sister', 'sister', 'son', 'brother']