Several years ago, I made a quilt just like you're describing from the clothes of a baby....probably the first two years of clothes , for a mother who had lost this child in a tragic accident. I used fusible tricot to iron to the back of the area I wanted to use for my 6 or 8 in block. (I can't remember the exact size, but you can tell by the size of the clothes what it needs to be. ) That helps prevent the stretching and gives it some body to sew with and to cut with. There's some waste of tricot by ironing on before cutting out the block, but it was well worth it since nearly all of these clothes were cotton knit. Of course, I cut the clothes apart at the shoulders and side seams before ever beginning. All the clothes had some cute little flowers or embroidered designs, etc which I used for the centers of the blocks. Then, I framed with different fabrics for the stripping/sashing. It made a darling quilt, and the mother was so grateful to have this "memory" of her precious child to keep forever. And, you definitely could use the extra "help" with all this cutting and preparing. Will make her appreciate it soooooo much more!!!