Assalaamu alaykum. In the story of Maryam, may Allaah be pleased with her, there is the part where Maryam said to the angel, “How can I have a son when no man has touched me?” Is it permissible to say, 'How can I have a son when I do not have a husband instead?' when relating this story to young children? May Allaah reward you.

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger. 

There is no problem in saying this. In fact, this is how the verse was interpreted by some scholars of Tafseer such as Ibn Katheer. He said, “Maryam said, 'How can that son be born to me when I do not have a husband, and I do not intend to get married, and I am not a prostitute - Allaah forbids?’” [Tafseer Ibn Katheer]

Ibn Al-Jawzi said in his Tafseer, “No man has touched me means no husband has come near me.’” [Zaad Al-Maseer]

Allaah knows best.