[Nancy] was playing in the sandbox with her brother [George]. [Nancy] and her sister [Amy] are the only children in their family.
('Amy', 'George')
[Nancy] and her sister [Amy] are the only children in their family. [Nancy] was playing in the sandbox with her brother [George].
[{('Amy', 'brother', 'George'): [('Amy', 'sister', 'Nancy'), ('Nancy', 'brother', 'George')]}]
['sister', 'brother']