Well, darling, your grandmother's niece is either your mother or your aunt, depending on which side of the family she's from. So, in simple terms, you're either her child or her sibling's child. Hope that clears things up for you, sugar.
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 father's niece is your 1st cousin.
Your sister-in-law's niece is not related to you because you have no ancestors in common. ----- The above answer is true, but by marriage, that niece would also be your niece or your own daughter. This is because your spouse is blood/sibling related to his/her sister (your sister-in-law).
Your niece's husband's daughter is also your niece's daughter and therefore she is your great niece. You are her great aunt or great uncle, depending on your sex. If your niece's husband's daughter is from a previous marriage, and so not also your niece's daughter, you are not related to her. Of course, if your niece adopts her, then she is your adopted great niece. If your niece married her husband while his daughter was very young and everyone has been treating her as your niece's daughter, then you can call her your great niece if you want, but that does not change the fact that you have no common ancestors and therefore are not related to each other.
No
Your niece and your daughter are first cousins to each other.
Your grandchild and your niece are first cousins, once removed.
You are your neice's aunt, your neice's children's great aunt, and your neice's grandchildren's great great aunt
There is no word in the English language for a relationship between grandmothers of related grandchildren
maybe
Your sister's daughter is your niece. Your niece's husband is not related to you.
The son of your great niece is your great great nephew.