One of our lady members has a sister and brother-in-law who are not members of the church. She asked her brother-in-law if he would study with me. He told her, "No!" Only with herself and his wife. So, this sister asked me if she would be wrong teaching them in the private setting of their home. She does not want to usurp authority over the man.
Since her brother-in-law refused to study with me or anyone else, I told her it would be all right.
Today, a member accused me of violating the Scriptures for telling her she could! My thoughts were with the purest of intentions and that if she didn't, who could? Do you believe I was wrong for telling her to teach the class?
If it were wrong for a woman to teach a man in all situations, there would have been no need to mention Priscilla's name in Acts 18:26. Aquila would have done all the talking and Priscilla would not have taught. Yet, this is not what the passage says. Luke tells us that both Priscilla and her husband, Aquila, taught Apollos. We note, though, that the setting was private.
We know that woman cannot teach in the public assembly (I Corinthians 14:34-35). But you are not describing such a situation.
The passage in I Timothy 2:11-12 says, "Let a woman learn in silence with all submission. And I do not permit a woman to teach or to have authority over a man, but to be in silence." The word silence here means "quiet submissiveness" and not absolute silence. Notice the contrast between learning in quietness and teaching with authority. The obvious conclusion is that among Christians, a woman is to learn in quietness and a man is to teach. But again, this is not the case being presented. The man involved is not a Christian. He is willing to learn of Christ from these two women, but he is not interested in listening to one of the men. They have the duty to explain the way of Christ to him. They need to do it in a quiet and gentle manner that befits a Christian woman, but they still can teach.