Niece as a noun is a daughter of someone's sibling, brother-in-law, or sister-in-law; either or one's brother ("fraternal niece") or of one's sister ("sororal niece"). while Nephew as a noun is a son of one's sibling, brother-in-law, or sister-in-law; either a son of one's brother (fraternal nephew) or a son of one's sister (sororal nephew).
Part of speech: noun
Definition: A daughter of someone's sibling, brother-in-law, or sister-in-law; either or one's brother ("fraternal niece") or of one's sister ("sororal niece").
Part of speech: noun
Definition: A son of one's sibling, brother-in-law, or sister-in-law; either a son of one's brother (fraternal nephew) or a son of one's sister (sororal nephew).
We hope you now know whether to use Niece or Nephew in your sentence.