It would seem like, to me, that if we took the string squares, put them right sides together with the strings going in opposite/opposing directions, marked a diagonal line, stitched on both sides, cut apart on the drawn line, we would have half of what she is trying to accomplish.
Then, take the two new squares, draw and stitch in the opposite direction ...
should give us the same configuration for the alternating blocks that she is proposing.
I will try and come back with pictures, but don't know how long it will take, since hubby is working on water issues and setting my new computer back to functioning order. <wave>