She could be your grandmother. Or she could be your great aunt.
If she's not your mother, that would make her your Aunt.
Your nephew's daughter is your great niece and you are her great Aunt (or Great Uncle).Correction:Your nephew's daughter is your grand niece. You are her grand aunt or grand uncle.
If your great great grandmothers were sisters, your common ancestors are your great great great grandparents. That makes you 4th cousins.
The child of your nephew is your great nephew (if a son) or your great niece (if a daughter).
Your daughter and your sister's son are first cousins to each other. Your sister's son's daughter (her granddaughter) and your daughter are first cousins, once removed.
If she's not your mother, that would make her your Aunt.
My ancestors
you will be his great great grand son/daughter..:)
First cousins twice removed.
Your daughter's daughter's son is your great grandson, and you are his great grandfather or great grandmother.
Your aunt is your daughter's great aunt. Your daughter is your aunt's great niece.
She is his great grandniece.
Your grandniece's daughter is your great-grandniece.
Your brother's daughter is your niece. Her daughter is your great niece.
Your nephew's daughter's son is your great-great nephew. Your nephew's daughter is your great niece.
Your mother's brother is you uncle and your daughter's great uncle. Your daughter is his great niece.
Great-niece.