I don't know the history of Sunbonnet Sue, but she fits the era of the 1930's to me.
I found a vintage Little Bo Peep quilt top at an estate sale a few months ago. The applique was beautiful. If I remember correctly, the girls on the left half of the quilt were facing right, and the ones on the right half were facing left. It was as if the girls were looking at each other. Perhaps that is what the lady had in mind with the Sunbonnet Sue's that you got.
In any case, I think you will have a wonderful quilt when you are finished.
Dayle