Children of your siblings are nieces and nephews. Children of your spouse's siblings are still called nieces and nephews, but you are not related to them by blood.
Your niece's children are your great nieces and great nephews.
If you are a woman, you are the great aunt of your niece's children. If you are a man, you are their great uncle. The children are your great nieces and nephews.
Certainly! Your sister's grandchildren are your great nieces and great nephews.
Your mother's sister is your aunt. Your mother's sister's husband is your uncle.Some of that uncle's nieces and nephews are your first cousins or your siblings, because they are the children of your mother and her siblings (other than your aunt's children).Some of that uncle's nieces and nephews are not related to you, because they are the children of his siblings, who are not related to you.
Nieces and nephews are the children of your siblings.
Your sister-in-law is either the wife of your brother or the sister of your spouse. The children of your brother's wife are your nieces and nephews, since they are also the children of your brother. In some cases they may be your sister-in-law's children from a previous marriage. Then they are not related to you at all. However, if they are very young, it may be convenient to call them your nieces and nephews anyway. The children of your spouse's sister are always your nieces and nephews.
Maybe. They are only related if they share a common ancestor. There are lots of possibilities and some of them will be related and some will not.
You are the aunt for those children. They are your nieces (girls) and nephews (boys).
If your great uncle is the brother of one of your grandparents, his wife is your great aunt but their nephews and nieces onher side are not related to you. Those nieces and nephews (and their children the great nieces and great nephews) have no ancestor who is also one of yourancestors.
Even thought you not related in genealogy sense you are related by marriage and you can say they are newphew and nieces in law.
Your children and your nieces are first cousins to each other.
The children of your husband's siblings are your nieces or nephews. Their children are your great-nieces or great-nephews.
They are your grand-nephews and grand-nieces or great-nephews and great-nieces.
Your mother's nieces' children are your mother's grand nephews or grand nieces. They are your first cousins, once removed.
Half aunts and uncles or half nieces and nephews.
Your great nieces or newfews
Your half-brother's children are your nieces and nephews, or your half-nieces and half-nephews if you insist on being very precise.
you would be their great great aunt
Your sister's female children are your nieces.
Your sister-in-law is either the wife of your brother or the sister of your spouse. In either case, her children are your nieces and nephews and her grandchildren are your great nieces and great nephews. You are great aunt or great uncle to her grandchildren. However, if her grandchildren are descended from children she had before she became your sister-in-law (i.e. from a previous marriage), neither her children nor her grandchildren are related to you.
Your sister's husband is your brother-in-law. Your brother-in-law's brother is not related to you and neither are his children. But he is your sister's brother-in-law and his children are your sister's nieces and nephews.
Your great uncle is your children's great great uncle. They are his great great nieces and great great nephews.
Your father's great nephew is the son of your father's niece or nephew. Your father's nieces and nephews are your first cousins. Their children are your father's great nieces and great nephews, and are your first cousins, once removed.
Your nephew's children are your great nephews and great nieces (or grand nephews and grand nieces).