Instead of Downy, you might consider using white vinegar in the rinse. I promise, the quilt won't come out smelling like a salad. The vinegar will help remove any remaining soap residue and also soften. We don't use fabric softeners at home due to my sensitivity to fragrances. I also agree with the recommendation to use a "Free & Clear" detergent if you have the option.
Cheers, K
(It looks like a beautiful quilt. I'm sure they will love it).