[Robert] and his brother [Pedro] played at jacks. [Pedro] and his sister [Tracy] were hoping for a snow day. [Louis]'s brother, [Robert], brought the car over to help him. [Tracy] and her daughter [Erika] went out for ice cream. [Tracy] got a cone and [Erika] got a sundae.
('Louis', 'Erika')
[Louis]'s brother, [Robert], brought the car over to help him. [Robert] and his brother [Pedro] played at jacks. [Pedro] and his sister [Tracy] were hoping for a snow day. [Tracy] and her daughter [Erika] went out for ice cream. [Tracy] got a cone and [Erika] got a sundae.
[{('Louis', 'niece', 'Erika'): [('Louis', 'sister', 'Tracy'), ('Tracy', 'daughter', 'Erika')]}, {('Louis', 'sister', 'Tracy'): [('Louis', 'brother', 'Pedro'), ('Pedro', 'sister', 'Tracy')]}, {('Louis', 'brother', 'Pedro'): [('Louis', 'brother', 'Robert'), ('Robert', 'brother', 'Pedro')]}]
['brother', 'brother', 'sister', 'daughter']