The answer
The exact meaning of certain idioms, such as "sister," in the holy Scripture is of Greek origin, and can be interpreted as being closely connected to a woman, like a sister, because of certain attributes, whether ideologically, philosophically, culturally, religiously, or even as distant relatives, etc.), but not necessarily to mean a close biological relative, nor as a wife.
Answered by His Eminence Metropolitan Youssef (opens in a new tab)