Seeing and touching quilts like these always makes me hold my breath while I try to absorb as much of it as I can. Several clues made her think this quilt was really old.
And I ALWAYS wish the maker had signed and dated her work. (In the quilt business I guess we say anything older than 1840 is REALLY OLD.) One clue to a pre-1860 quilt is the fringed edge.
Although the technique of quilting existed throughout history (quilted items have been discovered in Egyptian tombs, for example, and French knights used quilted jackets under their armor), quilts as we think of them didn't start showing up on the American scene until just prior to 1800.
The chasuble was probably deliberately made in patchwork so that if a priest were challenged, it could pass as a bedcover.
For example, the clearly defined cross would probably have escaped detection when the garment was folded or rolled.
I believe the earliest existing European quilts are a pair of whole cloth trapunto ones, telling the story of Tristan and Isolde dating from the early 1400's.
The oldest quilts in the Smithsonian collection go back to about 1780.