[Frances] took her son [Wesley] and granddaughter [Martha] out for pizza. [Martha]'s brother [Chris] cried because he could n't go.
('Frances', 'Chris')
[Frances] took her son [Wesley] and granddaughter [Martha] out for pizza. [Martha]'s brother [Chris] cried because he could n't go.
[{('Frances', 'grandson', 'Chris'): [('Frances', 'granddaughter', 'Martha'), ('Martha', 'brother', 'Chris')]}, {('Martha', 'brother', 'Chris'): [('Martha', 'father', 'Wesley'), ('Wesley', 'son', 'Chris')]}]
['granddaughter', 'father', 'son']