[Katherine] is taking a trip to see her sister [Helen]. [Michelle] it going back to Boston to visit her sister [Katherine] and her brother [Matthew].
('Matthew', 'Helen')
[Michelle] it going back to Boston to visit her sister [Katherine] and her brother [Matthew]. [Katherine] is taking a trip to see her sister [Helen].
[{('Matthew', 'sister', 'Helen'): [('Matthew', 'sister', 'Katherine'), ('Katherine', 'sister', 'Helen')]}, {('Matthew', 'sister', 'Katherine'): [('Matthew', 'sister', 'Michelle'), ('Michelle', 'sister', 'Katherine')]}]