I strongly suspect that the badge/brooch from South Wales will still exist.
Queen Alexandra was Princess of Wales for so long and kept all her other gifts from both North and South Wales that it is unlikely she didn't keep the South Wales badge.
I have never done a search to see if it has been worn by her or subsequent queens. But, we know that Queen Elizabeth the Queen Mother wore the bracelet, as well as some parts of the gift from North Wales..
The gift from South Wales.
I suspect that such an item would not be easy for a modern lady to wear.