Cain’s wife
Where did Cain's wife come from? The Bible does not mention any other daughters born to Adam and Eve before Cain was married. Maybe it just doesn't mention them? Or did God just create them?
The Bible does not answer your question specifically, but provides information for us to know the likelihood of the situation. All people are descended from Adam and Eve (Acts 17:26), who had other children in addition to Cain, Abel, and Seth (Genesis 5:4). Cain would have married a relative of his. The prohibition against marrying close family members did not come until much later in history and was formalized in the Mosaic regulations (Leviticus 18-20).