Your sister's son is your nephew and you are his aunt (if you are female) or his uncle (if you are male.
the realtionship between you and your sister'd son is "NEPHEW"
Your son's son is your grandson.
Your sisters son is your nephew.
Your sister's son is your nephew.
Neice or nephew no dummy its nephew
The boy is your nephew
Your son and your sisters child are first cousins. The granddaughter is out of synch by a generation. That will make them first cousins once removed.
Your granddaughter and your sister's grandson are second cousins.
Yes, she did. She had the relationship of a mother that a mother has with her son. As most mothers do.
Your younger brother's wife's sister's daughter would be your son's cousin.
Your sister's son is your nephew. Your son's daughter is your granddaughter. Your son and your sister's son are first cousins to each other. Your son's daughter and your sister's son are first cousins once removed to each other. Your grandchild and your sister's grandshild are second cousins to each other.
Uncle or Auntie.
If her son is from a previous relationship, then he would be your step-son.
If two people are brother and sister and the sister has a son, then: her brother is her son's uncle, and her son is her brother's nephew.
Your mothers sisters Granddaughter is your second cousin