She is my son's daughter.
granddaughter
He's my mother's brother.
uncle
They are my father's parents.
grandparents
She's my father's sister.
aunt
He is my aunt's husband.
uncle
They are my son's children.
grandchildren
He is my father's father.
grandfather
He is my son's son.
grandson
They are my uncle's children.
cousins
She is my mother's mother.
grandmother
She is my uncle's wife.
aunt