Niece
My brother's daughter - My sister's daughter - My sibling's daughter
Uncle
My mother's brother - My father's brother - My grandfather's son - My grandmother's son - My grandparents' son
Stepsister
My father's daughter - My mother's daughter - The daughter of my mom's boyfriend / husband - The daughter of my dad's girlfriend / wife
Brother-in-law
My sister's boyfriend/husband - My brother's boyfriend/husband - My boyfriend's brother - My husband's brother
Mother-in-law
My husband's mother - My boyfriend's mother - My wife's mother - My girlfriend's mother
Husband
My wife's partner - My children's father
Brother
My mother's son - My father's son - My granparent's grandson