[Frances] made hamburgers with her daughter [David] and grandson [Michael]. [Michael]'s brother [Bobby] loves hamburgers.
('Frances', 'Bobby')
[Frances] made hamburgers with her daughter [David] and grandson [Michael]. [Michael]'s brother [Bobby] loves hamburgers.
[{('Frances', 'grandson', 'Bobby'): [('Frances', 'daughter', 'David'), ('David', 'son', 'Bobby')]}, {('David', 'son', 'Bobby'): [('David', 'son', 'Michael'), ('Michael', 'brother', 'Bobby')]}]
['daughter', 'son', 'brother']