[Martha] is looking for a good gift for her sister [Pamela]. [Chris] and his sister [Pamela] went to brunch today at the new diner. [Charles] did n't get along very well with his sister [Martha] for some reason.
('Charles', 'Chris')
[Charles] did n't get along very well with his sister [Martha] for some reason. [Martha] is looking for a good gift for her sister [Pamela]. [Chris] and his sister [Pamela] went to brunch today at the new diner.
[{('Charles', 'brother', 'Chris'): [('Charles', 'sister', 'Martha'), ('Martha', 'brother', 'Chris')]}, {('Martha', 'brother', 'Chris'): [('Martha', 'sister', 'Pamela'), ('Pamela', 'brother', 'Chris')]}]
['sister', 'sister', 'brother']