Final answer:
The Spanish word that best completes the sentence is 'la sobrina', which means 'the niece'
Step-by-step explanation:
The Spanish word that best completes the sentence is la sobrina. 'Luisa es de Nelly' translates to 'Luisa is Nelly's...' Since Luisa is a female name, we need a feminine noun to complete the sentence, and 'la sobrina' is the correct choice as it means 'the niece' in Spanish.
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