I was guessing the opposite from cashs mom: that it was made using a kit. A number of kits were available during that time, many with appliqué and many with the scalloped edge that the OP remembers. The problem is that there may be no record of many of those kits. When scholars started looking at quilt designs, kits were seen as ubiquitous and put down as not requiring creativity. As a result, many were not chronicled as part of any of the projects to record existing quilts and patterns.
OP may be lucky enough to stumble on to what she is looking for, but more likely will need to create her own pleasing design that she can say is inspired by her ancestor’s quilt.