Illinois, try visualizing the pattern with gridlines extending all the way up and all the way across. The sashing ends up having a bunch of half-square triangles and a solid block, each the same size as the center block of the friendship star that forms on the sashing.
You can either make a bunch of friendship stars and then add sashing by creating a bunch of half-square triangles and solid blocks to align around four of your ready-made stars. ( On the schematic ignore the friendship stars on the outside as those are all sashing-related stars if you want to make friendship stars and then merge them into the quilt.)
or
line up your quilt by rows and then web your stars together.