[Michael] asked his grandmother, [Frances], to read him a bedtime story. [Frances] read him Hansel & Gretel, which the boy always loved. [David] and her son [Michael] went to the zoo with [David]'s brother [Joshua].
('Joshua', 'Frances')
[David] and her son [Michael] went to the zoo with [David]'s brother [Joshua]. [Michael] asked his grandmother, [Frances], to read him a bedtime story. [Frances] read him Hansel & Gretel, which the boy always loved.
[{('Joshua', 'mother', 'Frances'): [('Joshua', 'sister', 'David'), ('David', 'mother', 'Frances')]}, {('David', 'mother', 'Frances'): [('David', 'son', 'Michael'), ('Michael', 'grandmother', 'Frances')]}]
['sister', 'son', 'grandmother']