[Nancy] and her sister [Lillian] went shopping at the mall. [Nancy]'s daughter [Heidi] stayed home to study.
('Lillian', 'Heidi')
[Nancy] and her sister [Lillian] went shopping at the mall. [Nancy]'s daughter [Heidi] stayed home to study.
[{('Lillian', 'niece', 'Heidi'): [('Lillian', 'sister', 'Nancy'), ('Nancy', 'daughter', 'Heidi')]}]
['sister', 'daughter']