The Samaritans are probably mostly descended from the 10 northern tribes (although according to 2 Kings 17 the king of Assyria brought in settlers from elsewhere after he captured Samaria--probably the deportation of the earlier population of the kingdom of Israel was only partial).
I know that Sarah was not a “Jew.” You are talking to someone who debates Rabbis on “Jewish” matters and has stumped them every time. Actually, “Jew,” or “Yehudit” was used as an epithet during the civil war between the Tribes and I would rather not use it to describe myself because I think it is a perjorative that the world at large chose to call us and Hebrews have adopted for common usage. It bothers me.
Hebrew was derived from HaIvri which means simply The People.
There is no such thing, really, as Jew-ish. Just as there is no such thing as Hebrew-ish or pregnant-ish. After Jacob, we were Israelites...but still HaIvri.
I am a kind of rebel within my religion. I don’t like the way it has been split into factions, and I don’t like the idea that “Jews” seek to defend ALL those who take the name for themselves without obedience to The Law. Reform=deform. Conservative Jews aren’t. I am a sort of stand-alone hardliner and would probably be considered a heretic.