Beth - the one you call Kumiko's handkerchief, I don't recognize it. I looked through my books on old Flanders and Binche, but couldn't find it. There are a few wide edgings with designed corners in Erdmute Wesenberg's SCHNEEVERWEHT UND DURCHGEDREHT. But neither one exactly matches your example. Of course the photo is small and at an angle, to it is hard to tell for sure.
Welcome. Please read all the NOTES. They explain our policies, and how the software works. Join any groups that interest you. We do have one for BINCHE. I am also learning Binche. If you have any questions, contact me and I'll try to help.