I've used denatured alchohol to remove pencil marks from the girls clothes and it works very well. Never used it on a quilt...but if you try a test on a scrap you'll find out if it will. Just run the quilt under cold water, saturate the area with denatured alcohol rub it in gently, then hang it to dry. When the alcohol evaporates it takes the remaining mark with it. Then just launder as usual. This works VERY well on those not-so-washable washable markers and water color paints as well Just run the stain under cool water till it runs clear, do the same thing with the alcohol. You can do this with permanent marker too...but you have to use the hottest water the fabric will tolerate letting it run until the water runs clear, then follow same steps with the alcohol. Good luck!! I sure hope you find a solution!