[Pamela] was sewing a sweater for her sister [Tina]. [Tina] and her sister [Mildred] are the only children in their family. [Irvin] and her sister [Pamela] decided to take a trip to Mexico together.
('Mildred', 'Irvin')
[Tina] and her sister [Mildred] are the only children in their family. [Pamela] was sewing a sweater for her sister [Tina]. [Irvin] and her sister [Pamela] decided to take a trip to Mexico together.
[{('Mildred', 'brother', 'Irvin'): [('Mildred', 'sister', 'Tina'), ('Tina', 'brother', 'Irvin')]}, {('Tina', 'brother', 'Irvin'): [('Tina', 'sister', 'Pamela'), ('Pamela', 'brother', 'Irvin')]}]
['sister', 'sister', 'brother']