[Pete] took his sister [Wilhelmina] and father [Francisco] out on his boat with [Wilhelmina]'s grandfather, [James].
('Francisco', 'James')
[Pete] took his sister [Wilhelmina] and father [Francisco] out on his boat with [Wilhelmina]'s grandfather, [James].
[{('Francisco', 'father', 'James'): [('Francisco', 'son', 'Pete'), ('Pete', 'grandfather', 'James')]}, {('Pete', 'grandfather', 'James'): [('Pete', 'sister', 'Wilhelmina'), ('Wilhelmina', 'grandfather', 'James')]}]
['son', 'sister', 'grandfather']