[James] is a benevolent grandfather, and [Chris] is his young grandson. [Chris] and his sister [Pamela] stood in line at the fair. [Pamela] and her sister [Martha] braided each other's hair before school.
('Martha', 'James')
[Pamela] and her sister [Martha] braided each other's hair before school. [Chris] and his sister [Pamela] stood in line at the fair. [James] is a benevolent grandfather, and [Chris] is his young grandson.
[{('Martha', 'grandfather', 'James'): [('Martha', 'sister', 'Pamela'), ('Pamela', 'grandfather', 'James')]}, {('Pamela', 'grandfather', 'James'): [('Pamela', 'brother', 'Chris'), ('Chris', 'grandfather', 'James')]}]
['sister', 'brother', 'grandfather']