What is the name of my sister's grandson's little brother's wife?

What you want to ask is, what's the name of my little brother's wife? Call her brother-in-law

Sister-in-law is a title, also called sister-in-law, which is found in most parts of the north. Refers to a man's address to his wife's sister-in-law.

Uncle, a standard first-class character (commonly used character) in modern Chinese, first appeared in Shuowen, and belongs to pictophonetic characters in Liu Shu. The basic meaning of uncle is uncle, which refers to the mother's brother or brother.