Yes I too think the table salt had something to do with your mother's death. If only home blood pressure meters were available back then. I wonder if the salt caused your mother's insomnia, rather than insomnia caused by loss of salt. I heard that salt could be stimulating if used incorrectly. One night I think I took in too much salt and felt like I had too much energy to sleep.
I envy people like George Burns who has something of an iron body. But maybe it's his good attitude that got him that far. Latest news say coffee helps with alzheimer's and heart disease. Martinis? Maybe it's the next secret to a long life. Wishing you many more years. :)