I don't think that is too "elementary" at all. I had an assignment like that
as a student is a college design class. Our group project was to make a quilt
for the AIDS quilt project. And we each made a square.
Quilts can be really basic, or advanced. It could have patchwork piecing or
not. You can teach stitchery and require students to demonstrate some mastery
of different stitches to make it more advanced.