I have only made one log cabin quilt but, here is what I learned. To make or change your lay out you need the same amount of blocks ie. 4x4 or 3x3 or 6x6 makes the best layout for a log cabin. I understand that the dark brown is not sashing from the picture and, pictures are not always color accurte, it might be too dark but I would not replace it. If it were me I would do as other have suggested and go ahead and add the rest of the dark brown a small light boarder and a wider dark boarder and as I always say " It is what it is." Your DD will love it and you will both be happy. IMHO