[Dale] likes playing catch with his sister [Lillian], but his brother [Nicholas] never wants to play.
('Lillian', 'Nicholas')
[Dale] likes playing catch with his sister [Lillian], but his brother [Nicholas] never wants to play.
[{('Lillian', 'brother', 'Nicholas'): [('Lillian', 'brother', 'Dale'), ('Dale', 'brother', 'Nicholas')]}]
['brother', 'brother']