Final answer:
The correct verb form to complete the sentence is 'recibió'.
Step-by-step explanation:
The correct verb form to complete the sentence is 'recibió'. The subject of the sentence is 'Mi hermana' (My sister), which is a third-person singular subject, so we use the verb form 'recibió' (received). Here, 'recibir' (to receive) is conjugated in the preterite tense to match the subject.
Learn more about Spanish verb conjugation