The cousin, after
pawning the ring with the knowledge of Katherine K., could have decided to
sell the ring to the pawnshop for additional cash. The pawnshop would then "legally" own the ring to sell to someone else, assuming as the pawnshop probably did that the cousin was the actual owner of the ring (the cousin's name, thanks to Katherine and the cousin's odd arrangement, was on all of the pawn shop documents).
If the cousin
did sell the ring to the pawnshop without the knowledge of or authorization by Katherine K., Katherine K. potentially could have a legal action to consider against the cousin and could report the theft of the ring to the police, but she would have no action to take against the pawn shop.
I agree with LdiJ, though, that what has been posted by Katherine K. is anything but clear.