personally I really am not superstitious and would finish the quilt in honor of my GGM and be proud of the heritage it comes from.
Peace
PS: just a thought. What if no one finished anything that a deceased person handled. Nothing would ever be acomplished in this world. I have lots of my mothers counted crossstitch hanging on my walls. It wouldn't be there if I haden't taken up the work of my mother and completed them. Her memory is always with me and that is a good thing.
peace again