It kind of depends. However, as the law is written, if the item can be considered general use for people of all ages, then it is not a children's item and not subjected to the law. If you photograph them on adults and tag them in adult categories, but people put them on their child anyway, that's not a child's item.
But, as LILGIRLCA stated, if the item looks like it's for children, that's enough to be considered for children under the law (that's actually the problem I'm having, I don't make my Gnomes for kids, but they look like they could be). If your headbands are clearly appealing to adults too, you might be safe.