if the quilt show posts signs asking that the quilts not be photographed then, and someone is selfish and sneaky enough to take pictures anyway, then certainly, no photos should be posted here.
if the quilt show permits photos, then it's ok to post a few of the member's photos here.
if the quilt show has a website with pictures available, it would be best to provide a link to that site instead of personal photos.
when photos are posted, the ethical and courteous thing is to include complete attribution: the name(s) of the quilt, the designer(s), the person(s) who made the quilt(s) and the person(s) who did the quilting.