Not knowing how old this woman is, but she probably thought you have a stash of left over fabric and could make it from that.
A friend of mine was asking me to crochet angels for her. She was in her mid 70's, a good friend and I did it without thinking twice. After making 4 of them, she mentions to me she has been giving them to friends. The next time she asked me for one I told her I was no longer making them, I was onto other projects. At one time she did offer to pay for them, but I declined since they were for her. It never occurred to me that she was giving them to others.