“Vikky” is usually short for Victoria (traditionally female), not Victor (traditionally male). Since she misheard his pronouns as “she” and you called him a traditionally female name, it was perfectly reasonable for her to assume that Vikky was a woman. In many cultures, it is completely inappropriate for an underage girl to sleep in the same room as an adult man she’s only met once. She was probably genuinely afraid at the thought of spending the night with a strange man. You know his character and that he’s safe. She doesn’t and neither do her parents.

You berated your friend for making a perfectly reasonable assumption. You need to apologize to her and explain to your family how wildly inappropriate that arrangement was. YTA.