Wow, that guy was a hammy actor that I don't think I can buy this one.
Google tells me that Mary Miller Jason was listed in a book about witches in York Maine, buried in the 'Old Burying Yard'. However, there is no Mary Miller Jason buried there, but there IS a Mary Nasson buried there, died in 1774, and her grave is known as the 'Witches Grave'. It seems unclear whether she really did practice herbal medicines and such, or if it got that name simply because it is such an interesting marker. There is a headstone, a flat slab that covers her body, and a 'footstone' at the other end. Here are a few pictures.