[Marie] took her son [Ronald] to the park. [Robert] was proud of his son, [Ronald]. [Louis] spent the day with his sister, [Marie], and his daughter [Nettie].
('Robert', 'Nettie')
[Robert] was proud of his son, [Ronald]. [Marie] took her son [Ronald] to the park. [Louis] spent the day with his sister, [Marie], and his daughter [Nettie].
[{('Robert', 'niece', 'Nettie'): [('Robert', 'brother', 'Louis'), ('Louis', 'daughter', 'Nettie')]}, {('Robert', 'brother', 'Louis'): [('Robert', 'son', 'Ronald'), ('Ronald', 'uncle', 'Louis')]}, {('Ronald', 'uncle', 'Louis'): [('Ronald', 'mother', 'Marie'), ('Marie', 'brother', 'Louis')]}]
['son', 'mother', 'brother', 'daughter']