[Cheryl] has an aunt named [Tracy] [Tracy] and her daughter [Erika] went out to dinner. [Pedro] 'wife [Dorothy] went with him to a cruise. [Dorothy]'s daughter [Cheryl] stayed home and studied.
('Pedro', 'Erika')
[Pedro] 'wife [Dorothy] went with him to a cruise. [Dorothy]'s daughter [Cheryl] stayed home and studied. [Cheryl] has an aunt named [Tracy] [Tracy] and her daughter [Erika] went out to dinner.
[{('Pedro', 'niece', 'Erika'): [('Pedro', 'sister', 'Tracy'), ('Tracy', 'daughter', 'Erika')]}, {('Pedro', 'sister', 'Tracy'): [('Pedro', 'daughter', 'Cheryl'), ('Cheryl', 'aunt', 'Tracy')]}, {('Pedro', 'daughter', 'Cheryl'): [('Pedro', 'wife', 'Dorothy'), ('Dorothy', 'daughter', 'Cheryl')]}]
['wife', 'daughter', 'aunt', 'daughter']