Is it possible that Eve had more children than anyone else in the ancient world before the flood?
This is the kind of question we can guess at the answer but never really know. We have no idea how long Eve lived. In the book of generations, Adam’s first mention of age is at the birth of Seth. He is 130 years old (Genesis 5:3).
We have no idea how old Adam was when Cain and Abel were born. We have no idea how much time passes from the creation of humans to the leaving of the Garden of Eden. We don’t know when time began. Did it begin at creation or when they ate the fruit from the Tree of the Knowledge of Good and Evil? Or did it begin when they left the garden?
We would assume that Adam and Eve are the same age because they were created at roughly the same time, as far as we understand. We don’t know when Eve died. Many of these questions are not answered by Scripture because they are not the central focus of the Bible.
Adam was 130 when he had the third son mentioned in Scripture. However, they had sons and daughters after Seth (Genesis 5:4). This raises other questions. Did they have sons and daughters after Cain and Abel, and before Seth? The Bible only mentions the parts of the family lines that matter to furthering the story of redemption.
Everything we want to know is not written in Scripture. God instructed the writers of Scripture through the inspiration of the Holy Spirit to record the matters that have to do with his salvation plan.
Adam lives for 800 years after the birth of Seth. Since it takes nine months for the birthing process, they could had at least 800 children, if Eve lived as long as Adam. That’s a lot of children. But again, we have no idea how long Eve lived. This also assumes Eve could have children up to the day she died.
With as many questions we have outside of the scope of the Bible, these are the only facts we can infer without further information. These are interesting issues we can think about and imagine, but they are not part of the story of redemption. The Bible was written so we could understand God’s plan of salvation and his ultimate destiny for those who believe in him.