I know this must seem indelicate to say so I hope this doesn't upset you but I would find some heavy stones to place over the ground where you bury her if it is somewhere wild. I'm afraid foxes will dig things up from quite deep. My OH's mother uses some wire placed over the area with stone/slabs holding it in place to prevent foxes digging things back up, she keeps chickens and it has happened on many occasions i'm afraid, even with the family cat when she passed so please take precautions as I know you would hate that.
I'm sorry you keep finding her things everywhere, it must be so upsetting. Time is a good healer. Thinking of you tonight