Patty....I totally relate to this old wives tale. Growing up, my mother wouldn't let me sew on Sunday because it was a day of rest. She had no problem with making me do housework, cooking, or cleaning. I think it had something to do with her being superstitous...bad luck and all to sew on Sunday. By golly now I do what I want to do and if the Spirits aren't happy...sew what?
By the way, that's a beautiful quilt...bet you couldn't have done a better job on it any other day of the week. lol.