[Frances] and her husband [James] made pancakes for their daughter [David]. [David]'s sister [Lena] ate waffles instead.
('Frances', 'Lena')
[Frances] and her husband [James] made pancakes for their daughter [David]. [David]'s sister [Lena] ate waffles instead.
[{('Frances', 'daughter', 'Lena'): [('Frances', 'daughter', 'David'), ('David', 'sister', 'Lena')]}, {('Frances', 'daughter', 'David'): [('Frances', 'husband', 'James'), ('James', 'daughter', 'David')]}]
['husband', 'daughter', 'sister']