Just MHO, but I would not put a border on it. Tell your SIL to get a dust ruffle, and leave the quilt as is. In the 30's, they did not put borders on quilts very often. It is gorgeous as is, I would bind it with an unbleached muslin binding. Good luck. I have one that my great grandmother hand pieced and my grandmother set together my machine, that I am going to hand quilt, that is original 30's fabrics, and I am not going to put any borders on it. Just MHO. Have fun with it and enjoy.