There is no special term in the English language to describe a relationship between you and your nephew's wife. To her, you are just "my husband's uncle." If she has children with your nephew, they will be your great nephews and great nieces and you will be their great uncle or great aunt.
Your niece's children are your great nieces or great nephews. The terms grand niece and grand nephew are sometimes used, as well.
You would be their great aunt or great nephew. You would refer to them as a great nephew. Most families just call them cousins.
A Great/Grand Uncle/Aunt.
great aunt
uncle
No. Your wife's niece is also your niece, but the husband of the niece is not related to you or to your wife.
Your brother's wife's kids would be your nieces or nephews.
niece in-law
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.
that would be your niece or if you want to be fussy then your niece in law!
Your wife's nephew is your nephew, but the English language has no relationship term for your nephew's wife. Just call her "my nephew's wife."
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.
If it's your sister then your sister, if it's your brother's wife then you sister-in-law
Yes. Persephone, his wife, is also his niece.
Your uncle-by-marriage's nephews might be you and your siblings. You are your uncle's nephew or niece.They might be the children of your aunt's siblings (your aunt being his wife), in which case they are your cousins.If they are your uncle's nephews by virtue of being children of his siblings, they are no relation to you at all.
Your nephew's wife is your Niece-in-Law, whether she is caring for a child from a previous marriage or not. Few people would care to be that precise, however, so most will probably just call her your Niece.
Jensen currently has 2 nephews, Logan (the oldest) and Lincoln. They're the kids of his older brother Josh and his wife.