Your mother's second husband.
stepfather
It's you mom's mom.
grandmother
Your grandparents' parents.
great-grandparents.
They are your uncle's or aunt's children.
cousins
It's your brother's sister.
sister
Your dad's brother.
uncle
Your dad's wife.
mother
A brother or sister who was born at the same time as you.
twin
Your mom's sister.
aunt
Your sister's or brother's son.
nephew
Your wife's or husband's mother.
mother-in-law
Your dad's second wife.
stepmother
Your wife's or husband's father.
father-in-law
Your sister's or brother's daughter.
niece