Thank you all.
Yes, the photo is the one on Wikitree, and it is also on a number of Ancestry public trees. I got it from the Quilters' Guild, but I expect they got it from Ancestry.
Both the Guild's curator and i thought there was something wrong! So, Jim1, that is not really bad news. It confirms our suspicions. I would love to know why you date it to the 1870s. Is it her clothes? What is it about them? Some Ancestry trees have her birth in 1805, not 1787. But no sources anywhere, and I cannot find it myself. I have messaged the person who created the Wikitree page, but no answer yet.
Anyway, if we could more or less agree on a later date, that would eliminate her from being the quilter, I think. The quilt is dated to around 1800.
I would be grateful for any more thoughts, thank you.