Occasionally I climb out on little twigs of some of my side branches in search of clues that might help me to chip away at my brickwalls.That's what I'm doing now....
I searched this Alexander family for "Elizabeth and Robert" and found this post.What intrigues me about your post is that one of the counties mentioned in your post is where "my" particular Elizabeth's mother and stepfather lived.
Elizabeth Morgan married Robert Alexander in Madison Co., KY about 1809 (that county's marriage records are online).Elizabeth's mother was Susannah, maiden name unknown, who married second to a William Saltsman in 1795, Nelson Co., KY.William dropped the "S" from Saltsman/Salsman and is later found as Alsman.He and Susannah and at least 2 of their sons moved to Franklin, Union, and finally Rush Co. in Indiana.
Of course, it could just be a coincidence, but the first daughter in your list is named Susan---maybe it was actually Susannah?Also, sons were named John, William, Abraham, and Moses........the names of Elizabeth's 4 half-brothers.
I hope this proves of help to you......if you think this is your line, please drop me a line.Thanks!