Llanfair-is-gaer, is basically the parish based at what is now called Y Felinheli, formally known as Port Dinorwic. Llanddeiniolen is a neighbouring parish slightly to the north of it. Large new industrial towns such as Bethesda, didn't respect traditional parish boundaries that were formed in the Middle Ages and didn't respect the changes of the Industrial Revolution. I suspect that she died in Bethesda, which traversed both parishes, but there was uncertainty about the actual parish that "that" part of Bethesda was in.
