I am sure you are not wasting your time - just do something quick in colors that your mother loves. I have found that Thermore (it is a polyester) is the lighest/thinnest batting I can find. They use it in quilted clothing and table runners a lot. I too am wondering if the dense quilting just made it hard for her to move the quilt around. I think I might make 2 quick tops, quilt one myself (loosely) using the Thermore batting and then sending the 2nd one to be tied.