[Richard] and his sister [Anna] stood in line at the fair. [Anna] took her sister [Natasha] out for dinner to celebrate her birthday. [Leonard] always enjoyed playing with his sister, [Natasha], when they were growing up.
('Leonard', 'Richard')
[Leonard] always enjoyed playing with his sister, [Natasha], when they were growing up. [Anna] took her sister [Natasha] out for dinner to celebrate her birthday. [Richard] and his sister [Anna] stood in line at the fair.
[{('Leonard', 'brother', 'Richard'): [('Leonard', 'sister', 'Natasha'), ('Natasha', 'brother', 'Richard')]}, {('Natasha', 'brother', 'Richard'): [('Natasha', 'sister', 'Anna'), ('Anna', 'brother', 'Richard')]}]
['sister', 'sister', 'brother']