I would totally forget about any pink. If grandma wants a rag quilt then just do that. BUT I would use the light blue gray color and some white to make a pleated ruffle on the edge. White as the sashing. It's pretty busy material so it needs to be tamed. You could also make a fringe border. Just forget the pink. White would make it pop and bring in the "girly factor". Stick with the colors on the selvage edges on the fabrics.