To speak about family, you should know the proper vocabulary. Here is the vocabulary connected with family members.
Relatives - members of a family
Grandfather - the father of a person’s mother or father
Grandmother - the mother of a person’s mother or father
Aunt - the sister of your mother or father, or the wife of your uncle
Uncle - the brother of your mother or father, or the husband of your aunt
Cousin - the child of your aunt and uncle
Father-in-law - the father of someone’s husband or wife
Mother-in-law - the mother of someone’s husband or wife
Brother-in-law - the husband of your sister or brother, or the brother of your husband and wife
Sister-in-law - the wife of your brother or sister, or the sister of your husband or wife
Nephew - a son of your sister or brother, or a son of the sister or brother of your husband or wife
Niece - a daughter of your brother or sister , or a daughter of your husband’s or wife’s brother or sister
Widower - a man whose wife has died and who has not married again
Widow - a woman whose husband has died and who has not married again
Stepfather - the man who is married to someone’s mother but who is not their real father
Stepmother - the woman who is married to someone’s father but who is not their real mother
Godfather - a male godparent
Godmother - a female godparent
Single-parent family - a family with one parent (a mother or a father)
Atsauce:
http://dictionary.cambridge.org