[David] has a son named [Michael]. [David]'s mother is [Frances]. [Michael] adores his sister [Marie].
('Frances', 'Marie')
[David] has a son named [Michael]. [David]'s mother is [Frances]. [Michael] adores his sister [Marie].
[{('Frances', 'granddaughter', 'Marie'): [('Frances', 'daughter', 'David'), ('David', 'daughter', 'Marie')]}, {('David', 'daughter', 'Marie'): [('David', 'son', 'Michael'), ('Michael', 'sister', 'Marie')]}]
['daughter', 'son', 'sister']