Thanks again, Nottsgirl1.
With a birth date of 1764, she would have been 63, so 65 at death is a pretty close estimate. Her husband, Johnson, gave his age as 80 in 1841 when he would have been about 76 in reality. Age was a bit irrelevant when no-one was going to give you a pension at 65!
I agree, the 1827 burial is the correct one so sensationalist journalism is nothing new (but I expected better things from the Gentleman's Magazine.)
Yes, I had seen that Daniel Diggle had had a beer named in his honour.