Your relationship to your nephew's daughter is that of a great-aunt or great-uncle.
Here's a breakdown:
- Your nephew is the son of your sibling (brother or sister).
- Therefore, your nephew's children are your grandnieces and grandnephews.
- Specifically, your nephew's daughter is your great-niece.
In simpler terms:
- Your sibling had a child (your nephew).
- Your nephew had a child (your great-niece).
Thus, you are the parent's sibling's parent, or the great-aunt or great-uncle.
