[Martha] and [Charles] had a picnic at the park. They had sandwiches and salad. [Lena] and her son [Charles] went to visit her mother [Frances] on Sunday afternoon. They ate dinner and talked.
('Frances', 'Martha')
[Lena] and her son [Charles] went to visit her mother [Frances] on Sunday afternoon. They ate dinner and talked. [Martha] and [Charles] had a picnic at the park. They had sandwiches and salad.
[{('Frances', 'granddaughter', 'Martha'): [('Frances', 'daughter', 'Lena'), ('Lena', 'daughter', 'Martha')]}, {('Lena', 'daughter', 'Martha'): [('Lena', 'son', 'Charles'), ('Charles', 'sister', 'Martha')]}]
['daughter', 'son', 'sister']