Your brother's sister is your daughter's aunt, and your daughter is your brother's, and his sister's, niece.
Your sister's daughter is your niece. Your sister's daughter's son (your sister's grandson) is your great nephew.
Your sister's daughter is your niece.
Your sister's daughter and your daughter are first cousins to each other. Your sister's daughter's daughter (her granddaughter) is first cousin once removed to you daughter. Your granddaughter and your sister's granddaughter are second cousins to each other.
bhagina
Your sister's daughter is your niece.
Your daughter-in-law's sister is not related to you, but is your son's sister-in-law.
Your sister's daughter and your sister's brother are niece and uncle to each other. The daughter is the niece of the brother and the brother is uncle to the daughter.
Your brother or sister's daughter is called 'your niece.'
You are the great aunt/uncle of your sister's son's daughter, and your sister's son's daughter is your great niece.
Your sister is your son's aunt. Your sister's daughter is your sons first cousin. Your sister's daughter's son (your sister's grandson) is your son's first cousin, once removed.
Your daughter is your sister's niece. Your daughter's son is her great nephew.