[Marie]'s daughter, [Michelle], asked her mom to read her a story. [Lizzie] took her sister [Michelle] out for dinner to celebrate her birthday. [John] is son of [Marie]. [Robert] went to the baseball game with his son [John]
('Robert', 'Lizzie')
[Robert] went to the baseball game with his son [John] [John] is son of [Marie]. [Marie]'s daughter, [Michelle], asked her mom to read her a story. [Lizzie] took her sister [Michelle] out for dinner to celebrate her birthday.
[{('Robert', 'daughter', 'Lizzie'): [('Robert', 'son', 'John'), ('John', 'sister', 'Lizzie')]}, {('John', 'sister', 'Lizzie'): [('John', 'sister', 'Michelle'), ('Michelle', 'sister', 'Lizzie')]}, {('John', 'sister', 'Michelle'): [('John', 'mother', 'Marie'), ('Marie', 'daughter', 'Michelle')]}]
['son', 'mother', 'daughter', 'sister']