They are first cousins once removed.
Your great nephew's children are your great great nieces and great great nephews. You are their great great aunt or great great uncle.
There is none. "This is George, my niece's husband." In most families he would referred to as a nephew.
Your great nephew's children are your great great nieces and great great nephews. You are their great great aunt or great great uncle.
Your borther-in-law's children are your nieces and nephews. You are their uncle or aunt, as is your spouse.
Your nephew's baby would be your grand-nephew or grand-niece. You would be their grand-uncle or grand-aunt.
Your husband's nephew is also your nephew, and you are his aunt. Remember that if your father has a married brother, the brother is your uncle and the brother's wife is your aunt , with no mention of one being related by marriage and the other not. They are simply your aunt and uncle. The same applies to your relationship to your husband's sibling's children. You are simply their aunt.
Your nephew's children are your great nephews and great nieces (or grand nephews and grand nieces).
where is the real niece and nephew of Bernie Mack
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 brother's children would be your nieces and nephews. Your nephew's children would be great-nieces and great-nephews.
Staying with Aunt Wanda
does ti have a nephew named Michael