[Richard] loved going to the park with his grandmother, [Frances]. [Anna] and her sister [Natasha] went to the basketball game. [Anna] invited [Richard] to meet them there, since she is his sister.
('Frances', 'Natasha')
[Richard] loved going to the park with his grandmother, [Frances]. [Anna] and her sister [Natasha] went to the basketball game. [Anna] invited [Richard] to meet them there, since she is his sister.
[{('Frances', 'granddaughter', 'Natasha'): [('Frances', 'grandson', 'Richard'), ('Richard', 'sister', 'Natasha')]}, {('Richard', 'sister', 'Natasha'): [('Richard', 'sister', 'Anna'), ('Anna', 'sister', 'Natasha')]}]
['grandson', 'sister', 'sister']