[Nancy] took her son [Robert] shopping for new school clothes. They had a good time. [Nancy] is getting married. She is looking forward to her sister, [Lillian], attending. They have n't seen each other since [Lillian] relocated to California with her husband 3 years ago.
('Robert', 'Lillian')
[Nancy] took her son [Robert] shopping for new school clothes. They had a good time. [Nancy] is getting married. She is looking forward to her sister, [Lillian], attending. They have n't seen each other since [Lillian] relocated to California with her husband 3 years ago.
[{('Robert', 'aunt', 'Lillian'): [('Robert', 'mother', 'Nancy'), ('Nancy', 'sister', 'Lillian')]}]
['mother', 'sister']