'Sister' in the Bible

And Hadad findeth grace in the eyes of Pharaoh exceedingly, and he giveth to him a wife, the sister of his own wife, sister of Tahpenes the mistress;

and the sister of Tahpenes beareth to him Genubath his son, and Tahpenes weaneth him within the house of Pharaoh, and Genubath is in the house of Pharaoh in the midst of the sons of Pharaoh.