[Lynn] invited her sisters, [Lena] and [Cindy], to a party. [Cindy]'s sister, [David], recently started acting.
('David', 'Lena')
[Cindy]'s sister, [David], recently started acting. [Lynn] invited her sisters, [Lena] and [Cindy], to a party.
[{('David', 'sister', 'Lena'): [('David', 'sister', 'Lynn'), ('Lynn', 'sister', 'Lena')]}, {('David', 'sister', 'Lynn'): [('David', 'sister', 'Cindy'), ('Cindy', 'sister', 'Lynn')]}]
['sister', 'sister', 'sister']