[Cheryl] needed to go to the store. [Cheryl] asked her sister [Heather] for a ride. [Pedro] took his daughter [Annie] to the zoo on Saturday. [Pedro]'s wife [Dorothy] could n't come as she had to work that day. [Heather] and her sister [Annie] are the only children in their family.
('Dorothy', 'Cheryl')
[Pedro] took his daughter [Annie] to the zoo on Saturday. [Pedro]'s wife [Dorothy] could n't come as she had to work that day. [Heather] and her sister [Annie] are the only children in their family. [Cheryl] needed to go to the store. [Cheryl] asked her sister [Heather] for a ride.
[{('Dorothy', 'daughter', 'Cheryl'): [('Dorothy', 'husband', 'Pedro'), ('Pedro', 'daughter', 'Cheryl')]}, {('Pedro', 'daughter', 'Cheryl'): [('Pedro', 'daughter', 'Annie'), ('Annie', 'sister', 'Cheryl')]}, {('Annie', 'sister', 'Cheryl'): [('Annie', 'sister', 'Heather'), ('Heather', 'sister', 'Cheryl')]}]
['husband', 'daughter', 'sister', 'sister']