Many thanks Angie. I am really grateful to you for going to this trouble for me.
As Nell pointed out, the Warminster Registration District covers a very broad area and it's perfectly possible that she was buried in one of the surrounding villages. It's equally possible that there wasn't any headstone, so all things considered this will have to rest until more information comes to light.
Thanks a lot for making time to do this looking for me.
Kind regards
Philip