What are traders, you ask? These are typically small handmade items intended for swapping with other people. Most traders are "hat crafts" that get attached to a camp hat, but crests and pins can also be traded. Once you have a fun trading experience, it's hard to stop looking for new and unique crafts – using recycled objects, beads, pins, felt, and much more. In the US, they are called SWAPS (Special Whatchmacallits Affectionately Pinned or Shared With A Pal). Girls all over the world create traders to exchange.
If your daughter wants to make traders over the summer, for camp or other Guiding events, there are plenty of websites with creative ideas. You can also attach a little label with your name, unit, or district.