[Ashley] had to pick up her grandson [Robert] and his sister, [Linda], from school today.
('Ashley', 'Linda')
[Ashley] had to pick up her grandson [Robert] and his sister, [Linda], from school today.
[{('Ashley', 'granddaughter', 'Linda'): [('Ashley', 'grandson', 'Robert'), ('Robert', 'sister', 'Linda')]}]
['grandson', 'sister']