'Sister's' in the Bible

[As for] your sister's nakedness, [whether] your father's daughter or your mother's daughter, [whether] {born at home} or {born abroad}, you must not expose their nakedness.

You are not to marry a woman as a rival to her sister and have sexual intercourse with her during her sister’s lifetime.

And if a man shall take his sister, his father's daughter, or his mother's daughter, and see her nakedness, and she see his nakedness; it is a wicked thing; and they shall be cut off in the sight of their people: he hath uncovered his sister's nakedness; he shall bear his iniquity.