[Frances] and her daughters [Lena] and [David] made pies. [Lena]'s son [Chris] made a cake instead.
('Frances', 'Chris')
[Frances] and her daughters [Lena] and [David] made pies. [Lena]'s son [Chris] made a cake instead.
[{('Frances', 'grandson', 'Chris'): [('Frances', 'daughter', 'Lena'), ('Lena', 'son', 'Chris')]}, {('Frances', 'daughter', 'Lena'): [('Frances', 'daughter', 'David'), ('David', 'sister', 'Lena')]}]
['daughter', 'sister', 'son']