[Heidi] borrowed some money from her brother [Kevin]. [Kevin] and his sister [Louise] went to the park.
('Heidi', 'Louise')
[Heidi] borrowed some money from her brother [Kevin]. [Kevin] and his sister [Louise] went to the park.
[{('Heidi', 'sister', 'Louise'): [('Heidi', 'brother', 'Kevin'), ('Kevin', 'sister', 'Louise')]}]
['brother', 'sister']