[Robert] braided his sister [Linda]'s hair. [Nancy] took her daughter, [Linda], to lunch.
('Robert', 'Nancy')
[Robert] braided his sister [Linda]'s hair. [Nancy] took her daughter, [Linda], to lunch.
[{('Robert', 'mother', 'Nancy'): [('Robert', 'sister', 'Linda'), ('Linda', 'mother', 'Nancy')]}]
['sister', 'mother']