Craft copyright

I got a wake up call from a knitter a few days ago. She asked me if she can sell a hat I designed. I gave the pattern as a free gift to anyone that is interested to knit it for their personal use, and that is what I  told her. She said she is going to sell it anyway. Here is what I found on e-how: Crafts generally receive copyright protection under the "visual arts" category of copyright law. Copyright distinguishes between a useful item (such as a sweater or a clay bowl), which cannot be copyrighted, and the pattern or design of a useful craft and non-utility art pieces, which can be protected by copyright. Copyright is automatic: as soon as you design a new knitting pattern or necklace, you own the copyright. The U.S. Copyright Office offers a registration service, however, and for a fee issues official certificates of Registration that can be sold or used as stand-alone evidence of ownership in court. It means that your instructions (pattern) are protected, but not the items that are made from these instructions. I have to say that I didn't check the copyright issue before and I feel annoyed and disappointed. All my free patterns are not available for now. I'll keep you posted.