Thanks, again, for everyone's comments. You all are so very wonderful.
I like to think I'm a pretty rational and low-key person, and when I woke up the next morning after finding the quilt, I felt back to myself. DIL will be DIL, no matter what. Whether or not it was Divine Providence, I did find the quilt that is laying beautifully and lovingly on my bed. :D I spent Friday and Saturday helping DIL with her garage sale, and we had a blast. We both love crosswords, so we sat with a big book of puzzles working on them. I don't think we ever stopped talking. So all is okay --- she and I get along so well; I've let go of the bad feelings; and I have the quilt in my little paws, and it "ain't going nowhere!"