She is clearly defined as an Egyptian woman. She was probably acquired while Abraham and Sarah were in Egypt (Genesis chapter 12) and is first mentioned in Genesis chapter 16. A lot happens in those chapters and it is difficult to assess timeline...but Abraham is promised an heir in Chapter 15 and this is important.
My notes have Genesis chapter 16 as a transitional chapter...and there were 10 years between the promise of an heir and Sarah giving her maid to Abraham as a wife. (Genesis 16:1) If that is true, Hagar's age probably cannot be between 17-20 as most theologians believe..unless she was aquired in Egypt as a young child. To me, mid twenties seems more likely...but I could be wrong!
A concubine was a legal wife of lesser standing. While Abraham was not the first to have more than one wife, Hagar is usually referred to as the first concubine.(Lamech, from the family of Cain, is the first polygamist in the Bible).
Hagar is the mother of Ishmael--who also is the father of nations (his family records are found in Genesis chapter 25 and he has twelve sons just like Isaac).
There are at least two incidents of strife between Sarah and Hagar in the Bible. the first time Hagar leaves as Sarah treats her poorly out of jealousy (Genesis 16) and an angel appears and tells her she must go back. In chapter 21, after Isaac is born (To Sarah), Sarah see Ishmael mocking Isaac and has Abraham send Hagar and Ishmael away--where they settled in the wilderness of Paran and his mother got an Egyptian wife for him.
I think the notable thing about Hagar is that she did what some of us try to do--she initially tried to escape from her problem and run away from Sarah. Eventually she did the right thing and returned. she went through some tough times, but later in life was rewarded as her son became father of what is essentially the Arabic nations.
Hagar is detailed well in scripture as your list reveals. Thank you.
select one here...