Hi,
I did somewhat the same thing except I used scraps from clothes I had made my children and I appliqued either strips as in the pic below or 5 blocks that were 10" finished with diffrent things on them and then filled in with 2 1/2" squares. This way I did not have to worry about diffrent types of material or the grain or that sort of thing and I also did not have to worry about running out of the clothing material. I just bought the material for the 2 1/2' blocks and what I appliqued on. I made one for each grandchild as they were born. So I have made 7 of them. Just plan it out before you start. Good luck and I hope you will post pictures.