[Clarence] was happy that his son [Nicholas] was doing well in college. [Nicholas] and his sister [Nancy] walked to school together every day, since they only lived two blocks away from the school.
('Clarence', 'Nancy')
[Clarence] was happy that his son [Nicholas] was doing well in college. [Nicholas] and his sister [Nancy] walked to school together every day, since they only lived two blocks away from the school.
[{('Clarence', 'daughter', 'Nancy'): [('Clarence', 'son', 'Nicholas'), ('Nicholas', 'sister', 'Nancy')]}]
['son', 'sister']