When Cain was marked from being harmed, who were the people that were coming against him. I ask because if Eve were was birthing all these people she could only bear one child a year till she died. Possibly have several multiple births. Not sure how long she lived but she may have had 600-800 children in her life.
In the Book of Genesis account we’re a very compressed account of events. We don’t know how many years passed in Genesis 4 but we do know that everyone alive was related to Cain. In Genesis 4:17 we’re told that Cain built a city and named it after his son. Genesis 4:17-23 covers 8 generations of Cain’s descendants.
I believe chapter 4 focused on Cain’s line but overlapped chapter 5 which tells us Adam and Eve were also having other children (Genesis 5:4), one of whom became Cain’s wife (Genesis 4:17). At the same time, their children were having children (Genesis 4:26). In summary there could have been many people around.
The point is all we can do is trust that the word of God is an accurate summary of events that are pertinent to us.