IPA: /niːs/
KK: /nis/
A daughter of your brother or sister, or the daughter of your brother-in-law or sister-in-law.
My niece loves to play with her toys.
The word 'niece' originates from Old French 'niece' (meaning daughter of a brother or sister), which in turn comes from Latin 'neptis' (meaning granddaughter or niece). The term refers specifically to the daughter of one's sibling.
Think of the Old French word 'niece' which means the daughter of a brother or sister — this helps you remember that a niece is a sibling's daughter.