A warning about Oxyclean. The first time I used I let it sit too long and ruined a very expensive piece of clothing. I had pretreated per the directions, but the top did not go into the machine as planned and had the product on too long. It completely bleached the top.
Play, if you still have scraps from the quilt, why not pass them along, so your dil can try different products on scraps to check the impact. If you do not have those scraps, but have something similar, perhaps she could try them too? Or make up a couple quilt sandwiches of the same or similar fabrics for her to test.