'Sister' in the Bible

But if the unbelieving depart, let him depart. A brother or a sister is not under bondage in such cases: but God hath called us to peace.

So by your knowledge the weak brother or sister, for whom Christ died, is destroyed.

For this reason, if food causes my brother or sister to sin, I will never eat meat again, so that I may not cause one of them to sin.

Have we not power to lead about a sister, a wife, as well as other apostles, and as the brethren of the Lord, and Cephas?