Niece is to nephew as sister is to brother.
Your nephew's sister is your niece.
Your niece's brother is your nephew.
Your brother's or sister's son is your nephew. Your nephew's or niece's child is your grand-nephew or grand-niece.
sister
Nephew is to sibling as brother is to sibling. In this case, nephew and brother are both types of siblings.
yes... a niece is a girl and a nephew is a boy
You would be a neice or nephew, neice if a girl and nephew if a guy.
Your fathers brothers are your uncles. You are their nephew, or niece.
It depends if your niece's or nephew's parent is your brother or sister.
niece/nephew
Your brother's daughter is your niece, her daughter is your great niece and her granddaughter is your great great niece. It works the same for nephew, aunt, and uncle.