she is no archaeologist (her theories re Arthur and the Isle of Man are not treated seriously by any academic scholar I know - her background is in English)- there is virtually no archaeological evidence on St Patrick's Island - when the Irish round tower + hall + the later cathedral were built they destroyed whatever was there before (there is not much cover over the rock) - see the report on St Germain's Cathedral and the pagan lady dig - there was a supposed neolithic settlement by the water's edge but it is thought much of that was lost in erosion and change of sea level.