According to Thompson, her grandmother Adriana Porter's family were the carriers of a secret tradition of folk witchcraft that had come down through Sarah Arnot Cook and Wealthy Trask (Trash) from the latter's seventeenth-century ancestors.
Thompson's claims to be an hereditary witch have little independent support, since she states that she destroyed the original version of her grandmother's lore-book after copying its contents, and recopied her own book several times throughout her lifetime.
While a recent book by Robert Mathiesen and Theitic documents a long history of occultism within Thompson's ancestry, including the seventeenth-century alchemist Jonathan Brewster, as well as several of the families on both sides of the Salem witch trials of 1692, there is no direct evidence of the veracity of Thompson's claims as she, her mother and any others who could have provided first-hand information are all deceased, and any written documentation has not been made public.
In 1975, Thompson had an article entitled "Wiccan-Pagan Potpourri" published in Green Egg magazine issue #69 (Ostara 1975), for which she is best known.
[2] Although Thompson wrote that this version of the Rede was in its original form, this declaration is disputed for several reasons, but primarily as the language of the poem refers to Wiccan concepts that are not known to have existed in her grandmother's lifetime.
Another claim is that it is adapted from a speech given by Doreen Valiente at a dinner sponsored by the Witchcraft Research Association and mentioned in volume one (1964) of the Pentagram, a United Kingdom pagan newsletter then being published.
Valiente did publish a similarly worded and entitled poem The Witches Creed in her 1978 book, "Witchcraft for Tomorrow".
[4] The Green Egg publication listed her by-line as "Lady Gwen Thompson, Welsh Tradition Wicca", which was a tag of their own creation.
This has led to numerous instances of Thompson's Tradition and its practitioners being labeled as Celtic Wicca despite her stated objections and preference for the term Traditionalist.