In the Western World- yes.
You mother's sister is your aunt, but a god daughter does not have to be a blood relative. If that's the case, there's no special word for what you're doing.
yes...
Yes, your niece is the daughter of your sibling (sister or brother), so there is continuity of "blood" (i.e., genetic descent) from your common parent(s), assuming your sister/brother and her/his daughter are not adopted.
Probably yes if you have no blood relate to her.
There is no actual blood relationship. In most instances you call them the sister of your daughter in-law. Or just introduce them by name and let people guess if there is a connection.
Well she,s not blood related to you. But she is related to you by marriage and she'syou niece in law.
Your brother in law's daughter is not a blood relative; however, by marraige she is your niece. She is the neice of your wife. Any relative of your wife becomes a relative of yours when you become "one" in marriage.
Yes, a half sister can share in her fathers estate if she was the blood daughter of the father.
she would be your half-sister (since she shares half your blood)
That could be your daughter. It could also be someone with no blood relationship to you if it is actually your brother-in-law's niece. It could also be your niece and in most families you would just refer to her as a niece.
Of course she is otherwise they wouldn't be sisters they would be half sisters or something like that man you're stupid
Your niece is the daughter of your sister. If you have more than one sister, you can have nieces who are also the nieces of your sister, since they are daughters of the other sister.