[Martha]'s grandfather [James] took her and her sister [Pamela] out to dinner. [Pamela] was playing hide-and-seek with her sister [Tina].
('James', 'Tina')
[Martha]'s grandfather [James] took her and her sister [Pamela] out to dinner. [Pamela] was playing hide-and-seek with her sister [Tina].
[{('James', 'granddaughter', 'Tina'): [('James', 'granddaughter', 'Pamela'), ('Pamela', 'sister', 'Tina')]}, {('James', 'granddaughter', 'Pamela'): [('James', 'granddaughter', 'Martha'), ('Martha', 'sister', 'Pamela')]}]
['granddaughter', 'sister', 'sister']