Block #3 is called Marly. This center area is just flying geese but has a twist to it - that bottom small goose gets rectangular sides instead of the little triangles.
I had to play with my math a bit since I don't have the special ruler that the tutorial showed but it came out just perfectly 6.5" square. And then the center section fits into the sawtooth star. Each of these blocks will fit into the RSC15 Sampler along with some spacer blocks containing 9-patches. I also cut a few 2.5" squares of the pink and the white to save for the 9-patches. I'm going to do a scrappy white-on-white background for this sampler quilt.