[Ronald] loved his mother, [Marie]. [Pedro] and his nephew [Ronald] went hunting together last weekend. [Robert] and his wife [Marie] got married in Spain. [Heather] was ill, that's why she could n't go to school. She was with her mother [Pedro] all day.
('Robert', 'Heather')
[Robert] and his wife [Marie] got married in Spain. [Ronald] loved his mother, [Marie]. [Pedro] and his nephew [Ronald] went hunting together last weekend. [Heather] was ill, that's why she could n't go to school. She was with her mother [Pedro] all day.
[{('Robert', 'niece', 'Heather'): [('Robert', 'brother', 'Pedro'), ('Pedro', 'daughter', 'Heather')]}, {('Robert', 'brother', 'Pedro'): [('Robert', 'son', 'Ronald'), ('Ronald', 'uncle', 'Pedro')]}, {('Robert', 'son', 'Ronald'): [('Robert', 'wife', 'Marie'), ('Marie', 'son', 'Ronald')]}]
['wife', 'son', 'uncle', 'daughter']