[Pedro] and his sister [Marie] were wrapping gifts for Christmas. [Pedro]'s daughter [Cheryl] desperately wanted to join them. [Robert] is so proud of his son. [John] is the son's name. [John] bought a new refrigerator for his mother [Marie].
('Robert', 'Cheryl')
[Robert] is so proud of his son. [John] is the son's name. [John] bought a new refrigerator for his mother [Marie]. [Pedro] and his sister [Marie] were wrapping gifts for Christmas. [Pedro]'s daughter [Cheryl] desperately wanted to join them.
[{('Robert', 'niece', 'Cheryl'): [('Robert', 'brother', 'Pedro'), ('Pedro', 'daughter', 'Cheryl')]}, {('Robert', 'brother', 'Pedro'): [('Robert', 'son', 'John'), ('John', 'uncle', 'Pedro')]}, {('John', 'uncle', 'Pedro'): [('John', 'mother', 'Marie'), ('Marie', 'brother', 'Pedro')]}]
['son', 'mother', 'brother', 'daughter']