Answer: The correct pronoun to be used is "her".
Step-by-step explanation:
When we use neither/nor and either/or, the subject we must take into consideration when deciding on how to conjugate verbs or which pronoun/adjective to use is the one that comes after the words "nor/or". If that subject is singular, so is the pronoun and the verb conjugation.
In the sentence we are analyzing here, the subject after "nor" is Rebecca. It is singular and it refers to a girl/woman. That's why we should use the possessive adjective "her".