[Nicholas]'s sister, [Nancy], was so happy to have him home. He was home from college. [Nancy] took her son [Robert] to school this morning because he missed the bus.
('Nicholas', 'Robert')
[Nicholas]'s sister, [Nancy], was so happy to have him home. He was home from college. [Nancy] took her son [Robert] to school this morning because he missed the bus.
[{('Nicholas', 'nephew', 'Robert'): [('Nicholas', 'sister', 'Nancy'), ('Nancy', 'son', 'Robert')]}]
['sister', 'son']