You may give it away, trade it, or sell it. You simply cannot copy the pattern instructions and illustrations and sell them as your own work product.
Does it work if the teacher of the class looks at this design, makes her own pattern and instructions with a little tweak her or there and gives it to her class participants? I've seen so m any quilts that are so so similar but they are sewn up in current updated fabric and called something else, even sold as something else. For example "spools" or "hour glass". I have directions in a book for an "exploding star" that I've seen stitched up and called something else or all the various chevron patterns, just to mention a few.