Subsequently to her first imprisonment the witchcraft act was repealed and replaced with a law making it illegal to claim to speak to the dead for the purpose of making money, unless you could actually speak to the dead (Or it was for entertainment purposes). This law change was spearheaded by a Labour politician named Thomas Brooks who was himself a spiritualist.

This law was then itself repealed and replaced by EU marketing regulations in 2008.

Edit: Incidentally while she was charged under the witchcraft act. The reason she was reported was not for being a medium, but for being a BAD medium. Her performance at seances was so awful, having misidentified two separate ghosts (Actually Duncan herself in a white costume twice) as two female members of the same audience member’s family who both happened to be alive, that her audience went to the cops.

Edit 2: Rephrased the previous edit a bunch.